Tag Archives: Platform_Update

What’s new in Wear OS 6

Posted by Chiara Chiappini – Developer Relations Engineer

This year, we’re excited to introduce Wear OS 6: the most power-efficient and expressive version of Wear OS yet.

Wear OS 6 introduces the new design system we call Material 3 Expressive. It features a major refresh with visual and motion components designed to give users an experience with more personalization. The new design offers a great level of expression to meet user demand for experiences that are modern, relevant, and distinct. Material 3 Expressive is coming to Wear OS, Android, and all your favorite Google apps on these devices later this year.

The good news is that you don’t need to compromise battery for beauty: thanks to Wear OS platform optimizations, watches updating from Wear OS 5 to Wear OS 6 can see up to 10% improvement in battery life.1

Wear OS 6 developer preview

Today we’re releasing the Developer Preview of Wear OS 6, the next version of Google’s smartwatch platform, based on Android 16.

Wear OS 6 brings a number of developer-facing changes, such as refining the always-on display experience. Check out what’s changed and try the new Wear OS 6 emulator to test your app for compatibility with the new platform version.

Material 3 Expressive on Wear OS

moving image displays examples of Material 3 Expressive on Wear OS experiences
Some examples of Material 3 Expressive on Wear OS experiences

Material 3 Expressive for the watch is fully optimized for the round display. We recommend developers embrace the new design system in their apps and tiles. To help you adopt Material 3 Expressive in your app, we have begun releasing new design guidance for Wear OS, along with corresponding Figma design kits.

As a developer, you can get access the Material 3 Expressive on Wear OS using new Jetpack libraries:

These two libraries provide implementations for the components catalog that adheres to the Material 3 Expressive design language.

Make it personal with richer color schemes using themes

moving image showing how dynamic color theme updates colors of apps and Tiles
Dynamic color theme updates colors of apps and Tiles

The Wear Compose Material 3 and Wear Protolayout Material 3 libraries provide updated and extended color schemes, typography, and shapes to bring both depth and variety to your designs. Additionally, your tiles now align with the system font by default (on Wear OS 6+ devices), offering a more cohesive experience on the watch.

Both libraries introduce dynamic color theming, which automatically generates a color theme for your app or tile to match the colors of the watch face of Pixel watches.

Make it more glanceable with new tile components

Tiles now support a new framework and a set of components that embrace the watch's circular form factor. These components make tiles more consistent and glanceable, so users can more easily take swift action on the information included in them.

We’ve introduced a 3-slot tile layout to improve visual consistency in the Tiles carousel. This layout includes a title slot, a main content slot, and a bottom slot, designed to work across a range of different screen sizes:

moving image showing some examples of Tiles with the 3-slot tile layout
Some examples of Tiles with the 3-slot tile layout.

Highlight user actions and key information with components optimized for round screen

The new Wear OS Material 3 components automatically adapt to larger screen sizes, building on the Large Display support added as part of Wear OS 5. Additionally, components such as Buttons and Lists support shape morphing on apps.

The following sections highlight some of the most exciting changes to these components.

Embrace the round screen with the Edge Hugging Button

We introduced a new EdgeButton for apps and tiles with an iconic design pattern that maximizes the space within the circular form factor, hugs the edge of the screen, and comes in 4 standard sizes.

moving image of a sreenshot representing an EdgeButton in a scrollable screen.
Screenshot representing an EdgeButton in a scrollable screen.

Fluid navigation through lists using new indicators

The new TransformingLazyColumn from the Foundation library makes expressive motion easy with motion that fluidly traces the edges of the display. Developers can customize the collapsing behavior of the list when scrolling to the top, bottom and both sides of the screen. For example, components like Cards can scale down as they are closer to the top of the screen.

moving image showing a TransformingLazyColumn with content that collapses and changes in size when approaching the edge of the screens. .
TransformingLazyColumn allows content to collapse and change in size when approaching the edge of the screens

Material 3 Expressive also includes a ScrollIndicator that features a new visual and motion design to make it easier for users to visualize their progress through a list. The ScrollIndicator is displayed by default when you use a TransformingLazyColumn and ScreenScaffold.

moving image showing side by side examples of ScrollIndicator in action
ScrollIndicator

Lastly, you can now use segments with the new ProgressIndicator, which is now available as a full-screen component for apps and as a small-size component for both apps and tiles.

moving image showing a full-screen ProgressIndicator
Example of a full-screen ProgressIndicator

To learn more about the new features and see the full list of updates, see the release notes of the latest beta release of the Wear Compose and Wear Protolayout libraries. Check out the migration guidance for apps and tiles on how to upgrade your existing apps, or try one of our codelabs if you want to start developing using Material 3 Expressive design.

Watch Faces

With Wear OS 6 we are launching updates for watch face developers:

    • New options for customizing the appearance of your watch face using version 4 of Watch Face Format, such as animated state transitions from ambient to interactive and photo watch faces.
    • A new API for building watch face marketplaces.

Learn more about what's new in Watch Face updates.

Look for more information about the general availability of Wear OS 6 later this year.

Library updates

ProtoLayout

Since our last major release, we've improved capabilities and the developer experience of the Tiles and ProtoLayout libraries to address feedback we received from developers. Some of these enhancements include:

The example below shows how to display a layout with a text on a Tile using new enhancements:

// returns a LayoutElement for use in onTileRequest()
materialScope(context, requestParams.deviceConfiguration) {
    primaryLayout(
        mainSlot = {
            text(
                text = "Hello, World!".layoutString,
                typography = BODY_LARGE,
            )
        }
    )
}

For more information, see the migration instructions.

Credential Manager for Wear OS

The CredentialManager API is now available on Wear OS, starting with Google Pixel Watch devices running Wear OS 5.1. It introduces passkeys to Wear OS with a platform-standard authentication UI that is consistent with the experience on mobile.

The Credential Manager Jetpack library provides developers with a unified API that simplifies and centralizes their authentication implementation. Developers with an existing implementation on another form factor can use the same CredentialManager code, and most of the same supporting code to fulfill their Wear OS authentication workflow.

Credential Manager provides integration points for passkeys, passwords, and Sign in With Google, while also allowing you to keep your other authentication solutions as backups.

Users will benefit from a consistent, platform-standard authentication UI; the introduction of passkeys and other passwordless authentication methods, and the ability to authenticate without their phone nearby.

Check out the Authentication on Wear OS guidance to learn more.

Richer Wear Media Controls

New media controls for a Podcast
New media controls for a Podcast

Devices that run Wear OS 5.1 or later support enhanced media controls. Users who listen to media content on phones and watches can now benefit from the following new media control features on their watch:

    • They can fast-forward and rewind while listening to podcasts.
    • They can access the playlist and controls such as shuffle, like, and repeat through a new menu.

Developers with an existing implementation of action buttons and playlist can benefit from this feature without additional effort. Check out how users will get more controls from your media app on a Google Pixel Watch device.

Start building for Wear OS 6 now

With these updates, there’s never been a better time to develop an app on Wear OS. These technical resources are a great place to learn more how to get started:

Earlier this year, we expanded our smartwatch offerings with Galaxy Watch for Kids, a unique, phone-free experience designed specifically for children. This launch gives families a new way to stay connected, allowing children to explore Wear OS independently with a dedicated smartwatch. Consult our developer guidance to create a Wear OS app for kids.

We’re looking forward to seeing the experiences that you build on Wear OS!

Explore this announcement and all Google I/O 2025 updates on io.google starting May 22.


1 Actual battery performance varies.

What’s new in Watch Faces

Posted by Garan Jenkin – Developer Relations Engineer

Wear OS has a thriving watch face ecosystem featuring a variety of designs that also aims to minimize battery impact. Developers have embraced the simplicity of creating watch faces using Watch Face Format – in the last year, the number of published watch faces using Watch Face Format has grown by over 180%*.

Today, we’re continuing our investment and announcing version 4 of the Watch Face Format, available as part of Wear OS 6. These updates allow developers to express even greater levels of creativity through the new features we’ve added. And we’re supporting marketplaces, which gives flexibility and control to developers and more choice for users.

In this blog post we'll cover key new features, check out the documentation for more details of changes introduced in recent versions.

Supporting marketplaces with Watch Face Push

We’re also announcing a completely new API, the Watch Face Push API, aimed at developers who want to create their own watch face marketplaces.

Watch Face Push, available on devices running Wear OS 6 and above, works exclusively with watch faces that use the Watch Face Format watch faces.

We’ve partnered with well-known watch face developers – including Facer, TIMEFLIK, WatchMaker, Pujie, and Recreative – in designing this new API. We’re excited that all of these developers will be bringing their unique watch face experiences to Wear OS 6 using Watch Face Push.

Three mobile devices representing watch face marketplace apps for watches running Wear OS 6
From left to right, Facer, Recreative and TIMEFLIK watch faces have been developing marketplace apps to work with watches running Wear OS 6.

Watch faces managed and deployed using Watch Face Push are all written using Watch Face Format. Developers publish these watch faces in the same way as publishing through Google Play, though there are some additional checks the developer must make which are described in the Watch Face Push guidance.

A flow diagram demonstrating the flow of information from Cloud-based storage to the user's phone where the app is installed, then transferred to be installed on a wearable device using the Wear OS App via the Watch Face Push API

The Watch Face Push API covers only the watch part of this typical marketplace system diagram - as the app developer, you have control and responsibility for the phone app and cloud components, as well as for building the Wear OS app using Watch Face Push. You’re also in control of the phone-watch communications, for which we recommend using the Data Layer APIs.

Adding Watch Face Push to your project

To start using Watch Face Push on Wear OS 6, include the following dependency in your Wear OS app:

// Ensure latest version is used by checking the repository
implementation("androidx.wear.watchface:watchface-push:1.3.0-alpha07")

Declare the necessary permission in your AndroidManifest.xml:

<uses-permission android:name="com.google.wear.permission.PUSH_WATCH_FACES" />

Obtain a Watch Face Push client:

val manager = WatchFacePushManagerFactory.createWatchFacePushManager(context)

You’re now ready to start using the Watch Face Push API, for example to list the watch faces you have already installed, or add a new watch face:

// List existing watch faces, installed by this app
val listResponse = manager.listWatchFaces()

// Add a watch face
manager.addWatchFace(watchFaceFileDescriptor, validationToken)

Understanding Watch Face Push

While the basics of the Watch Face Push API are easy to understand and access through the WatchFacePushManager interface, it’s important to consider several other factors when working with the API in practice to build an effective marketplace app, including:

To learn more about using Watch Face Push, see the guidance and reference documentation.

Updates to Watch Face Format

Photos

Available from Watch Face Format v4

The new Photos element allows the watch face to contain user-selectable photos. The element supports both individual photos and a gallery of photos. For a gallery of photos, developers can choose whether the photos advance automatically or when the user taps the watch face.

a wearable device and small screen mobile device side by side demonstrating how a user may configure photos for the watch face through the Companion app on the mobile device
Configuring photos through the watch Companion app

The user is able to select the photos of their choice through the companion app, making this a great way to include true personalization in your watch face. To use this feature, first add the necessary configuration:

<UserConfigurations>
  <PhotosConfiguration id="myPhoto" configType="SINGLE"/>
</UserConfigurations>

Then use the Photos element within any PartImage, in the same way as you would for an Image element:

<PartImage ...>
  <Photos source="[CONFIGURATION.myPhoto]"
          defaultImageResource="placeholder_photo"/>
</PartImage>

For details on how to support multiple photos, and how to configure the different change behaviors, refer to the Photos section of the guidance and reference, as well as the GitHub samples.

Transitions

Available from Watch Face Format v4

Watch Face Format now supports transitions when exiting and entering ambient mode.

moving image demonstrating an overshoot effect adjusting the time on a watch face to reveal the seconds digit
State transition animation: Example using an overshoot effect in revealing the seconds digits

This is achieved through the existing Variant tag. For example, the hours and minutes in the above watch face are animated as follows:

<DigitalClock ...>
  <Variant mode="AMBIENT" target="x" value="100" interpolation="OVERSHOOT" />

   <!-- Rest of "hh:mm" clock definition here -->
</DigitalClock>

By default, the animation takes the full extent of allowed time for the transition. The new interpolation attribute controls the animation effect - in this case the use of OVERSHOOT adds a playful experience.

The seconds are implemented in a separate DigitalClock element, which shows the use of the new duration attribute:

<DigitalClock ...>
  <Variant mode="AMBIENT" target="alpha" value="0" duration="0.5"/>
   <!-- Rest of "ss" clock definition here -->
</DigitalClock>

The duration attribute takes a value between 0.0 and 1.0, with 1.0 representing the full extent of the allowed time. In this example, by using a value of 0.5, the seconds animation is quicker - taking half the allowed time, in comparison to the hours and minutes, which take the entire transition period.

For more details on using transitions, see the guidance documentation, as well as the reference documentation for Variant.

Color Transforms

Available from Watch Face Format v4

We’ve extended the usefulness of the Transform element by allowing color to be transformed on the majority of elements where it is an attribute, and also allowing tintColor to be transformed on Group and Part* elements such as PartDraw and PartText.

The main exceptions to this addition are the clock elements, DigitalClock and AnalogClock, and also ComplicationSlot, which do not currently support Transform.

In addition to extending the list of transformable attributes to include colors, we’ve also added a handful of useful functions for manipulating color:

To see these in action, let’s consider an example.

The Weather data source provides the current UV index through [WEATHER.UV_INDEX]. When representing the UV index, these values are typically also assigned a color:

moving image demonstrating an overshoot effect adjusting the time on a watch face to reveal the seconds digit

We want to represent this information as an Arc, not only showing the value, but also using the appropriate color. We can achieve this as follows:

<Arc centerX="0" centerY="0" height="420" width="420"
  startAngle="165" endAngle="165" direction="COUNTER_CLOCKWISE">
  <Transform target="endAngle"
    value="165 - 40 * (clamp(11, 0.0, 11.0) / 11.0)" />
  <Stroke thickness="20" color="#ffffff" cap="ROUND">
    <Transform target="color"
      value="extractColorFromWeightedColors(#97d700 #FCE300 #ff8200 #f65058 #9461c9, 3 3 2 3 1, false, clamp([WEATHER.UV_INDEX] + 0.5, 0.0, 12.0) / 12.0)" />
  </Stroke>
</Arc>

Let’s break this down:

    • The first Transform restricts the UV index to the range 0.0 to 11.0 and adjusts the sweep of the Arc according to that value.
    • The second Transform uses the new extractColorFromWeightedColors function.
        • The first argument is our list of colors
        • The second argument is a list of weights - you can see from the chart above that green covers 3 values, whereas orange only covers 2, so we use weights to represent this.
        • The third argument is whether or not to interpolate the color values. In this case we want to stick strictly to the color convention for UV index, so this is false.
        • Finally in the fourth argument we coerce the UV value into the range 0.0 to 1.0, which is used as an index into our weighted colors.

The result looks like this:

side by side quadrants of watch face examples showing using the new color functions in applying color transforms to a Stroke in an Arc
Using the new color functions in applying color transforms to a Stroke in an Arc.

As well as being able to provide raw colors and weights to these functions, they can also be used with values from complications, such as HR, temperature or steps goal. For example, to use the color range specified in a goal complication:

<Transform target="color"
    value="extractColorFromColors(
        [COMPLICATION.GOAL_PROGRESS_COLORS],
        [COMPLICATION.GOAL_PROGRESS_COLOR_INTERPOLATE],
        [COMPLICATION.GOAL_PROGRESS_VALUE] /    
            [COMPLICATION.GOAL_PROGRESS_TARGET_VALUE]
)"/>

Introducing the Reference element

Available from Watch Face Format v4

The new Reference element allows you to refer to any transformable attribute from one part of your watch face scene in other parts of the scene tree.

In our UV index example above, we’d also like the text labels to use the same color scheme.

We could perform the same color transform calculation as on our Arc, using [WEATHER.UV_INDEX], but this is duplicative work which could lead to inconsistencies, for example if we change the exact color hues in one place but not the other.

Returning to the Arc definition, let’s create a Reference to the color:

<Arc centerX="0" centerY="0" height="420" width="420"
  startAngle="165" endAngle="165" direction="COUNTER_CLOCKWISE">
  <Transform target="endAngle"
    value="165 - 40 * (clamp(11, 0.0, 11.0) / 11.0)" />
  <Stroke thickness="20" color="#ffffff" cap="ROUND">
    <Reference source="color" name="uv_color" defaultValue="#ffffff" />
    <Transform target="color"
      value="extractColorFromWeightedColors(#97d700 #FCE300 #ff8200 #f65058 #9461c9, 3 3 2 3 1, false, clamp([WEATHER.UV_INDEX] + 0.5, 0.0, 12.0) / 12.0)" />
  </Stroke>
</Arc>

The color of the Arc is calculated from the relatively complex extractColorFromWeightedColors function. To avoid repeating this elsewhere in our watch face, we have added a Reference element, which takes as its source the Stroke color.

Let’s now look at how we can consume this value in a PartText elsewhere in the watch face. We gave the Reference the name uv_color, so we can simply refer to this in any expression:

<PartText x="0" y="225" width="450" height="225">
  <TextCircular centerX="225" centerY="0" width="420" height="420"
    startAngle="120" endAngle="90"
    align="START" direction="COUNTER_CLOCKWISE">
    <Font family="SYNC_TO_DEVICE" size="24">
      <Transform target="color" value="[REFERENCE.uv_color]" />
      <Template>%d<Parameter expression="[WEATHER.UV_INDEX]" /></Template>
    </Font>
  </TextCircular>
</PartText>
<!-- Similar PartText here for the "UV:" label -->

As a result, the color of the Arc and the UV numeric value are now coordinated:

side by side quadrants of watch face examples showing Coordinating colors across elements using the Reference element
Coordinating colors across elements using the Reference element

For more details on how to use the Reference element, refer to the Reference guidance.

Text autosizing

Available from Watch Face Format v3

Sometimes the exact length of the text to be shown on the watch face can vary, and as a developer you want to balance being able to display text that is both legible, but also complete.

Auto-sizing text can help solve this problem, and can be enabled through the isAutoSize attribute introduced to the Text element:

<Text align="CENTER" isAutoSize="true">

Having set this attribute, text will then automatically fit the available space, starting at the maximum size specified in your Font element, and with a minimum size of 12.

As an example, step count could range from tens or hundreds through to many thousands, and the new isAutoSize attribute enables best use of the available space for every possible value:

side by side examples of text sizing adjustments on watch face using isAutosize
Making the best use of the available text space through isAutoSize

For more details on isAutoSize, see the Text reference.

Android Studio support

For developers working in Android Studio, we’ve added support to make working with Watch Face Format easier, including:

    • Run configuration support
    • Auto-complete and resource reference
    • Lint checking

This is available from Android Studio Canary version 2025.1.1 Canary 10.

Learn More

To learn more about building watch faces, please take a look at the following resources:

We’ve also recently launched a codelab for Watch Face Format and have updated samples on GitHub to showcase new features. The issue tracker is available for providing feedback.

We're excited to see the watch face experiences that you create and share!

Explore this announcement and all Google I/O 2025 updates on io.google starting May 22.


* Google Play data for period 2025-03-24 to 2025-03-23

Build kids app experiences for Wear OS

Posted by John Zoeller – Developer Relations Engineer, and Caroline Vander Wilt – Group Product Manager

New Wear OS features enable ‘standalone’ watches for kids, unlocking new possibilities for Wear OS app developers

In collaboration with Samsung, Wear OS is introducing Galaxy Watch for Kids, a new kids experience enabling kids to explore while staying connected with their families from their smartwatch, no phone necessary. This launch unlocks new opportunities for Wear OS developers to reach younger audiences.

Galaxy Watch for Kids is rolling out to Galaxy Watch7 LTE models , with features including:

    • No phone ownership required: This experience enables the watch and its associated apps to operate on a fully standalone basis using LTE, and when available, Wifi connectivity. This includes calling, texting, games, and more.
    • Selection of kid-friendly apps: From gaming to health, kids can browse and request installs of Teacher Approved apps and watch faces onGoogle Play. In addition to approving and blocking apps, parents can also monitor app usage from Google Family Link.
    • Stay in touch with parent-managed contacts: Parents can ensure safer communications by limiting text and calling to approved contacts.
    • Location sharing: Offers peace of mind with location sharing and geofencing notifications when kids leave or arrive at designated areas.
    • School time: Limits watch functionality during scheduled hours of the day, so kids can focus while in school or studying.

Building kids experiences with standalone functionality enables you to reach both standalone and tethered watches for kids. Apps like Math Tango have already created great Wear OS experiences for kids. Check out the video below to learn how they built a rich and engaging Wear OS app.

Our new kids-focused design and content principles and developer guidance are also available today. Check out some of the highlights in the next section.

New principles and guidelines for development

We've created new design principles and guidelines to help developers take advantage of this opportunity to build and improve apps and watch faces for kids.

Design principle: Active and fun

Build engaging healthy experiences for children by including activity-based features.

A great example of this is the Odd Squad Time Unit app from PBS KIDS that encourages children to get up and be physically active. By using the on-device sensors and power-efficient platform APIs, the app is able to provide a fun experience all day and still maintain battery life of the watch from wakeup to bed time.

A circular timer display with a hexagonal background 'JUMP!' and '5 SECONDS REMAIN'. A gold hand points to the number 5. A colorful segmented ring surrounds the center of the timer.

Note that while experiences should be catered to kids, they must also follow the Wear OS quality requirements related to the visual experience of your app, especially when crafting touch targets and font sizes.

Content principle: Thoughtfully crafted

Consider adjusting your content to make it not only appropriate, but also consumable and intuitive for younger kids (including those as young as 6). This includes both audio and visual app components.

Tinkercast’s Two Whats?! And a Wow! app uses age-appropriate vocabulary and fun characters to aid in their teaching. It’s a great example of how a developer should account for reading comprehension.

A smartwatch face displays a cartoon bird with a speech bubble that says 'SWIPE TO VIEW YOUR OPTIONS!'. Yellow arrows point left and right with a large letter 'A' between them.

Development guidelines

New Wear OS kids apps must adhere to the Wear OS app quality guidelines, the guidelines for standalone apps, and the new Kids development guide.


Minimize impact on device battery

Minimize events that affect battery life over the course of one session. Kids use watches that provide important safety features for their parents or guardians, which depend on the device having enough battery life. Below are best practices for reducing battery impact.

      ✅ DO design for offline use cases so that kids can play without incurring network-related battery costs

      ✅ DO minimize tasks that require an internet or GPS connection

      🚫 DO NOT use direct sensor tracking as this will significantly reduce the battery life

      🚫 DO NOT include long-running animations


Choose a development environment

To develop kid-friendly apps and games you can use Compose for Wear OS, our recommended approach for building UI for Wear OS, as well as Unity for Android.

We recommend Unity for developing games on Wear OS if you’re familiar and comfortable with its workflows and capabilities. However, for games with only a few animations, Compose Animation should be sufficient and is better supported within the Android environment.

Be sure to consider that some Wear OS quality requirements may require custom Unity implementations, such as support for Rotary Input.

Originator’s MathTango showcases the flexibility and richness of developing with Unity:

A purple cartoon moose-like character with large antlers is displayed on a round smartwatch face. The name 'ISAAC' is shown below the character, along with the label 'NEW!'. A green arrow is visible in the top left corner of the screen.

Creating Watch Faces

Developing watch faces for kids requires the use of Watch Face Format. Watch faces should adhere to our content and design principles mentioned above, as well as our quality standards, including our ambient mode requirement.

The following examples demonstrate our Content Principle: Appealing. The content is relevant, engaging, and fun for kids, sparking their interest and imagination.

The Crayola Pets Watch Face comes with a great variety of customization options, and demonstrates an informative and pleasant watch face:

A circular watch face shows a cartoon character, the time (3:30), the date (Feb 10), and a battery indicator (89%).

The Marvel Watch Faces (Captain America shown) provide a fun and useful step tracking feature:

A round smartwatch face displays a cartoon Captain America, his shield, and the time (12:30). A step counter shows 650 steps. The Marvel logo is visible.

Kids experience publishing requirements

Developers looking to get started on a new kids experience will need to keep a few things in mind when publishing on the Play Store.

Expand your reach with Wear OS

Get ready to reach a new generation of Wear OS users! We've created all-new guidelines to help you build engaging experiences for kids. Here’s a quick recap:

With the Wear for Kids experience, developers can reach an entirely new audience of users and be part of the next generation of learning and enrichment on Wear OS.

Check out all of the new experiences on the Play Store!

Scaling Across Screens with Jetpack Compose @ Google I/O ‘24

Posted by Maru Ahues Bouza, Product Management Director, Android Developer

Scaling Across Screens with Jetpack Compose

The promise of Jetpack Compose has always been that a modern toolkit designed to build native UI can help you build better apps faster and easier. As more and more of you - 40% of the top 1k apps, in fact - use (and love) Compose, we’ve been working to extend those benefits you’re seeing on mobile to also help you build across form factors as well. At Google I/O 2024, we announced a lot of new updates for Compose that help you build across form factors, including Compose APIs to support adaptive layouts, and new updates for Compose TV and Wear OS. From foldables to wearables to TVs, Compose is delivering features built to make Android development faster and easier. Apps like yours are already using Compose to support more screens with less code.

When thinking about layouts - think adaptive

Yesterday, we announced a new set of Compose APIs for building adaptive layouts, using Material guidance. These APIs, now in Beta, provide new layouts and components that adapt as users expect when switching between small and large window sizes.

The libraries provide 3 new scaffolds that adapt to the different window sizes that users can place apps in on different types of devices, from phones to foldables to tablets and more.

3 new libraries that adapt to different window sizes

NavigationSuiteScaffold

NavigationSuiteScaffold helps make it easier to build navigation UI by automatically complying with Material guidelines to provide your users with an optimal experience based on their window size.

Material guidelines recommend using a navigation bar at the bottom of compact width windows such as most phones and a navigation rail on the size of medium width and expanded width windows. It used to be up to each app individually to handle swapping between these components; now NavigationSuiteScaffold does this for you by switching between the components when the window size changes.

Navigation bar

ListDetailPaneScaffold & SupportingPaneScaffold

The new library also has ListDetailPaneScaffold and SupportingPaneScaffold, which help you implement canonical layouts that we recommend in many cases - list-detail and supporting pane.

On a phone, you usually organize your app flow through screens. For example, clicking on an item on your list screen brings you to the detail screen.

Detaileds screen

When adapting to different window sizes, it helps to think of your app in terms of panes rather than screens. For a compact window size class, such as a phone, you might only display one pane. For an expanded window size class, you might show two, or more panes at the same time. ListDetailPaneScaffold and SupportingPaneScaffold help you build apps that easily switch between one and two pane layouts.

Different screen layouts

You can learn more about all three of these APIs and how to get started with them in the “Building UI with the Material 3 adaptive library” and “Building adaptive Android apps” technical sessions.

“Integrating SupportingPaneScaffold was effortless and quick. It enabled us to seamlessly organize primary and secondary content on To-Dos. Depending on the window size class, the supporting pane adjusts the UI without any additional custom logic. Delighting our users regardless of what device they use is a key priority for SAP Mobile Start.”
- Software Engineer on SAP Mobile Start

Compose for Wear OS

In the past year, adoption of Compose for Wear OS has grown 200%, showcasing the ease with which Compose allows developers to build for the watch form factor.

Recently we’ve seen top apps such as WhatsApp, Gmail and Google Calendar built entirely using Compose for Wear OS, and it’s the recommended way for building user interfaces for Wear OS apps.

At this year’s Google I/O, Compose for Wear OS is graduating visual improvements and fixes from beta to stable.

In the past year, we’ve added features such as SwipeToReveal, to give users additional means for completing actions, an expandableItem, to enhance the use of the smaller screen and show additional information where needed, and a range of WearPreview supporting annotations, for ensuring your app works optimally across the range of device sizes and font scales.

Compose for Wear OS previews usage in Android Studio
Compose for Wear OS previews usage in Android Studio

You can get started with Compose for Wear OS by taking the codelab and learn more about all the latest updates for Wear OS via the technical session.

Compose for Android TV

At Google I/O ‘24, we announced that Compose for TV 1.0.0 is now available in beta. Compose for TV is our recommended approach for building delightful UIs for Android TV OS. It brings all of the benefits of Jetpack Compose to your TV apps, making building beautiful and functional experiences in your app much faster and easier.

The latest updates to Compose for TV include better performance, input support, and a whole range of improved components that look great out of the box. New in this release, we’ve added lists, navigation, chips, and settings screens. We’ve also updated the developer tools in Android Studio to include a new project wizard to get a running start with Compose for TV.

The new TV Material Catalog app lets you explore components in Compose for TV with different themes and layouts, and our updated JetStream sample shows how it all fits together.

TV Material Catalog app in action

You can get started with Compose for TV by checking out the dedicated blog, the technical session or taking a look at the integration guides.

Jetpack Glance

Jetpack Glance 1.1.0 is now available in RC, bringing a new unit test library, Error UIs, and new components.

We have also released new Canonical Widget Layouts on GitHub, which are built on top of the Glance components, to allow you to get started faster with a set of layouts that align with best practices.

The first set of layouts are delivered as code samples and a matching figma design kit on Android UI Kit with more layouts coming later this year.

Lastly, we have new design guidance published on the UI design hub—check it out!

A sample of Compose across screens: Jetcaster

A sample of Compose across screens: Jetcaster

We have updated Jetcaster—one of our Compose samples—to adapt across phone, foldable and tablet screens, and added support for TV, Wear and homescreen widgets with Glance. Jetcaster showcases how Compose helps you to build across a range of devices using a shared architecture in a single project.

See how you can extract elements such as your data layer, and design system, to promote reuse and consistency while delivering an experience tailored to different form factors. You can dive directly into the code on GitHub.

Get started with Compose across screens

With these updates to Compose to help you build for tablets, foldables, wearables and TVs, it is a great time to get started! These technical sessions are a great place to learn more about all the latest updates:

Learn more about how SoundCloud supported more screens using 45% less code with Jetpack Compose!

"Our mobile Compose skills transferred directly to Compose for other form factors, The concepts and most APIs are the same across form factors” - Vitus Ortner, Android engineer at SoundCloud

What’s new in Wear OS – I/O ’24

Kseniia Shumelchyk, Android Developer Relations Engineer, and Garan Jenkin, Android Developer Relations Engineer

Wear OS has seen incredible growth and advancements over the past year. With watch launches from Pixel, Samsung and more, Wear OS grew its user base by 40% in 2023 and has users in over 160 countries and regions. And Wear OS has expanded to more brands including OnePlus, OPPO and Xiaomi. This growth has been accompanied by heavy investments in performance and power optimization.

In this blog post, we’ll be highlighting some of the key updates we announced at Google I/O this year, so let’s dive in and explore the latest advancements in Wear OS and how you can make the most of the platform.

Wear OS 5 Developer Preview

We’re excited to be releasing the Developer Preview of Wear OS 5, the next version of Google’s smartwatch platform arriving later this year, based on Android 14. Central to our release of Wear OS 5 is continuing to enhance battery life.

Wear OS 5 brings performance improvements over Wear OS 4. Tracking your workout is now more efficient; for example, running a marathon consumes up to 20% less power on Wear OS 5 than on Wear OS 4.

Wear OS 5 brings battery improvements over Wear OS 4 for longer work out tracking
Wear OS 5 brings battery improvements over Wear OS 4 for longer work out tracking

To help you develop power-efficient apps on Wear OS, we’ve released a new guide to conserve power and battery. Be sure to take a look!

Wear OS 5 is based on Android 14, which brings with it a number of developer-facing changes. Check out what’s changed and try the new Wear OS 5 emulator to test your app for compatibility with the new platform version.

Changes in Watch Faces development

Last year we introduced the Watch Face Format as part of Wear OS 4, and we’ve had a fantastic response, with 30% of watch faces in Google Play already using the format. It’s been great to see what you’ve all been able to create so far using the Watch Face Format!

Sample Watch faces created with Watch Face Format
Sample Watch faces created with Watch Face Format

We’re excited to bring you the next iteration of the Watch Face Format with Wear OS 5.

Additionally, we’re announcing some changes to existing watch face development using Jetpack Watch Face APIs. Starting from Wear OS 5, we are introducing restrictions to complications for watch faces built with AndroidX or the Wearable Support Library that will apply to some data sources, as well as Google Play publishing limitations to new watch faces built with these libraries.

Check out the Watch Faces blog post for full details on the new features in Watch Face Format and changes to watch faces development options.

Tooling and library updates

Jetpack Compose for Wear OS

Adoption of Compose on Wear OS has grown 200% in the past year, highlighting the ease with which Compose allows developers to build for the watch form factor. Recently we’ve seen top apps such as WhatsApp, Gmail and Google Calendar built entirely using Compose for Wear OS, and it’s the recommended way for building user interfaces for Wear OS apps.

With the 1.3 release of Jetpack Compose for Wear OS, we’ve graduated a number of visual improvements and fixes from beta to stable.

In the past year, we’ve added features such as SwipeToReveal, to give users additional means for completing actions, an expandable item, to enhance the use of the smaller screen and show additional information where needed, and a range of WearPreview supporting annotations, for ensuring your app works optimally across the range of device sizes and font scales.

Compose for Wear OS previews usage in Android Studio
Compose for Wear OS previews usage in Android Studio

And at Google I/O 2024, we announced a lot of new updates with Jetpack Compose that help you build across form factors, including Wear OS, read more in this blog and check out how SoundCloud supported more screens using 45% less code with Jetpack Compose.

Tiles and ProtoLayout

Wear OS tiles give users fast, predictable access to the information and actions they rely on most. Version 1.4 of the Jetpack Tiles library, currently in alpha, introduces preview support for Android Studio to help you quickly iterate on your Tile development while also helping you create optimal-looking tiles on a range of display sizes.

Previews can be seen starting in Android Studio Koala Feature Drop (Canary), with the following dependencies:

    • androidx.wear.tiles:tiles-tooling-preview:1.4.0-alpha02+
    • androidx.wear.tiles:tiles-tooling:1.4.0-alpha02+
    • androidx.wear:wear-tooling-preview:1.0.0+
@Preview(device = WearDevices.SMALL_ROUND)
fun smallPreview(context: Context) = TilePreviewData(
    onTileRequest = { request ->
        TilePreviewHelper.singleTimelineEntryTileBuilder(
            buildMyTileLayout()
        ).build()
    }
)
Tiles previews usage in Android Studio
Tiles previews usage in Android Studio

We’ve also introduced better means for your app to determine whether your tiles are in use, through the getActiveTilesAsync() method.

Within ProtoLayout’s stable version 1.1, as used by Tiles, we’ve introduced a number of changes, such as the following:

    • Gradient support in ArcLine.
    • Date-time formatting supports different time zones for dynamic data types.
    • Better text autosizing and ellipsizing options, and consistent font padding behavior.
    • Expandable spacers
    • Improved accessibility for Clickable elements

And from 1.2.0-alpha02, we’ve made it easier for your layouts to adjust appropriately for different display sizes by adding the setResponsiveContentInsetEnabled() method to PrimaryLayout, as well as updating it for EdgeContentLayout. To use this setter, update your code as follows:

PrimaryLayout.Builder(deviceParameters)
    .setResponsiveContentInsetEnabled(true)
    .setContent(
        // ...
    )
.build()

Easier testing for fitness apps

Android Studio Koala Feature Drop (Canary) brings a new sensor panel to make it easier to test use of Health Services in your Wear OS app. The panel allows you to configure capabilities of the device, set values of specific data types and stimulate events such as auto-pause and resume of exercises.

Sensor panel usage with Wear OS emulator in Android Studio
Sensor panel usage with Wear OS emulator in Android Studio

Check out this blog to learn more about tooling updates.

Larger Displays

With the momentum surrounding Wear OS, we’re seeing a wider variety of round screen sizes and resolutions, which provides more choices for the user.

We are releasing new guidelines on how to build responsive UIs for different watch display sizes, as well as updates to existing libraries to introduce adaptive layouts, and components.

Check out the ComposeStarter sample for Wear OS on Github to see how to take advantage of these updates in your app. Furthermore, we’ve updated the sample to provide examples of using tools to evaluate your layouts, including :

    • Previews - demonstrating use of WearPreviewDevices to visualize your layouts on a full range of device sizes and font scaling settings.
    • Screenshot testing - helping you detect issues and regressions in your layouts on different sized devices, with different font scales and locales, representative of real-world devices.

Start building for Wear OS now

There has never been a better time to start building for Wear OS! Be sure to check out Building for the future of Wear OS technical session to learn more about all the latest updates for Wear OS!

To get started:

We’re looking forward to seeing the experiences that you build on Wear OS!

Latest updates for watch faces on Wear OS

Posted by Anna Bernbaum – Product Manager, and Garan Jenkin – Developer Relations Engineer

At last year’s Google I/O, we launched the Watch Face Format for Wear OS. This year, as part of our continued partnership with Samsung, we are excited to share some new features that you can use to create exciting new watch face designs! These features are now supported in XML definitions, and later in the year, you’ll also see an update to Watch Face Studio to take advantage of them.

The Watch Face Format is the recommended way to create watch faces for Wear OS. The format makes it easier to create customizable and more power-efficient watch faces for devices that run Wear OS 4 or higher. The Watch Face Format is a declarative XML format, so there is no executable code involved in creating a watch face, and there is no code embedded in your watch face APK.

Additionally, in our move toward the Watch Face Format for watch face creation, we have also made some changes to watch face development.

New features in the Watch Face Format

Flavors

Flavors represent preset configurations for your watch face, available in the companion app:

Watch gallery

They allow the watch face developer to configure useful and attractive combinations of the watch face’s configuration options, and allow the user to visualize and select from these with ease.

We’ve now brought flavors to the Watch Face Format. For a full guide on adding them to your watch face, see the flavors reference.

Complications

We’re adding support for both “goal progress” and “weighted elements” complication types to the Watch Face Format:

circle chart with data saying 60% of goal progress and weight elements circle chart

    • Goal progress is perfect for data where the user has a target, but that target can be exceeded. A good example is step count.
    • Weighted elements can represent discrete subsets of data, showing their relative sizes, where you might otherwise use something like a pie chart.

Both of these complication types can be accessed through the [COMPLICATION.*] expression object. For full details, see the complication guidance.

Weather

Knowing at-a-glance what the weather will be like for the next hour, day, and beyond can make all the difference to a user’s plans! Unsurprisingly, having weather data as a data source in the Watch Face Format has been a common request, and we’re delighted to be able to introduce it in this latest version. You’ll now be able make watch faces like this:

circle chart with data saying 60% of goal progress and weight elements circle chart

Weather Basics

Weather in the Watch Face Format is accessed via the [WEATHER.*] expression object. You can use it in Condition and text Template statements and anywhere where expressions are supported.

For example, to show the current weather condition, use this template and expression:

<Template>Current weather conditions: %s
    <Parameter expression="[WEATHER.CONDITION_NAME]"/>
</Template>

The weather provider in the Watch Face Format supports a range of different metric types for the current day, including the following:

    • Current conditions
    • Temperature - current, minimum (low), and maximum (high)
    • UV index
    • Chance of rain

For the full range of data types and conditions, see the weather guide.

Forecasts

In addition to the current weather, you can access forecast data, both by hour and by day. For example, to access the forecast maximum temperature for tomorrow, use a template and set of expressions similar to the following:

<Template>Tomorrow max temp: %d°%s
    <Parameter expression="[WEATHER.DAYS.1.TEMPERATURE_HIGH]" />
    <Parameter expression="[WEATHER.TEMPERATURE_UNIT] == 1 ? &quot;C&quot; : &quot;F&quot;" />
</Template>

When using weather in the Watch Face Format, there are some further details to be aware of, such as checking for forecast availability or loading errors. For all of this and more, take a look at the weather guide.

Changes to Watch Face development

As we gather momentum behind the Watch Face Format, we’re announcing some changes to existing watch face development options.

We announced recently that only some complications will be available on Wear OS 5, for watch faces built with AndroidX or the Wearable Support Library. This restriction does not apply to watch faces that use the Watch Face Format.

Additionally, starting in early 2025 (specific date to be announced in Q4 2024), all new watch faces published on Google Play must use the Watch Face Format. Existing watch faces that use other libraries, such as AndroidX or the Wearable Support Library, can continue to receive updates without transitioning to the new format.

New resources

To make it easier to create watch faces using the Watch Face Format, we’ve published some more resources on GitHub.

You now have full access to the XSD specification, to help you build your own watch face generating tools.

We’ve also provided validators to check your XML for correctness and memory usage. These are the same checks run by Google Play, so it allows you to run these checks even before you submit your watch face for publishing.

Learn more

Get started with the latest version of the Watch Face Format.

Be sure to check out Building for the future of Wear OS technical session and What’s new in Wear OS at I/O 2024 blog post to learn more about all the latest updates for Wear OS!

Code snippets license:

Copyright 2023 Google LLC.
SPDX-License-Identifier: Apache-2.0

Get the big picture with Large Screens at Google I/O 2024

Posted by Fahd Imtiaz, Product Manager, Android Developer

With Android reaching more devices, from phones to foldables to Chromebooks, building apps that seamlessly adapt to different screen sizes and types has never been more crucial. At this year’s Google I/O, we covered building adaptable apps, increasing user productivity with key inputs like keyboard and stylus, and scaling games across surfaces.

Building adaptive apps

Throughout Google I/O 2024, we’ve talked a lot about how to build adaptive apps. With this shift, some of you may be asking “what makes an app truly adaptive?”

Adaptive apps take advantage of the full screen size they are on - whether that is a phone, a tablet, or a foldable. These apps adjust layout based on conditions, driving how your app’s layout should adapt. These conditions include things like changes to the size of the window, device posture or font size.

Adaptive apps dynamically adjust their layouts by swapping components, showing, or hiding content based on the available window size, compared to simply stretching UI elements. With ever evolving form factors and screen sizes, adaptability for your app to any window size unlocks the seamless experiences users demand today.

Now that you know what they are, how do you get started building adaptive apps? We strongly recommend using WindowSizeClasses as the opinionated breakpoints for your UI and we’re bringing you a variety of new Compose APIs that make it easier to implement common adaptive layouts.

Available now in beta, the new Compose adaptive layout libraries help you to make your UI look good across window sizes. From navigation UI to list/detail and supporting pane style layouts, we’re providing composables to make building an adaptive app easier than ever.

Check out these technical sessions to learn more:

Or get started by checking out the new documentation!

Increase user productivity on tablet and foldables

Tablets and foldables are great for consuming content but even better when it comes to creating content. That’s why leveraging input devices like stylus for more productive experiences is especially important for your users.

Improving your app’s stylus experience

Stylus users on Android can remain more productive with new support for handwriting in text fields. You no longer need to put down your stylus when you need to input some text into a text field. Stylus handwriting and gestures will work automatically if you are using standard text components including BasicTextField in Compose (1.7), EditText in Views and text input elements in WebView.

For stylus users, low latency is key to having a responsive inking experience. Reducing latency minimizes the amount of delay between when you move your stylus and when the ink appears on the screen, giving users a more authentic pen-to-paper experience. Based on developer feedback, we’ve introduced new APIs to make low latency easier for apps that use Canvas for rendering.

A great example of these libraries in practice is Infinite Painter, where the team reduced their inking latency by 5x.

Enhancing productivity with keyboard and mouse support

Next to the stylus, another essential input device is the physical keyboard that really shines when users need to do a lot of text input like long emails, documents or blog posts. As a developer, making it easy for users to navigate your app with keyboard navigation can set your app apart.

Users should be able to navigate to all elements in your app with just their keyboard. It’s also important that frequently used keyboard shortcuts are supported in your app. To help educate your users about shortcuts, consider making your keyboard shortcuts discoverable to users by adding entries to the system KeyboardHelper.

To improve the experience for keyboard, mouse, trackpad, and stylus users, we also recommend implementing hover states and keyboard focus. All interactive components should have a hover state and should show a visual cue to indicate which component has the keyboard focus.

You can learn more about all these improvements and more via the technical session, and our updated documentation and codelab.

Enhance productivity with pane expansion

Although larger window sizes allow showing multiple panes of content at once, users often want to focus on one specific pane at a time. By following the new guidance for pane expansion, users have the choice to see both panes at once, or resize them as they desire.

Google Calendar has added pane expansion to their supporting pane layout on expanded width window sizes, allowing users to resize to see more details of an event, or more information in their schedule.

Although larger window sizes allow showing multiple panes of content at once, users often want to focus on one specific pane at a time. By following the new guidance for pane expansion, users have the choice to see both panes at once, or resize them as they desire.

Google Calendar has added pane expansion to their supporting pane layout on expanded width window sizes, allowing users to resize to see more details of an event, or more information in their schedule.

This feature will be supported by activity embedding in Android 15, and is also planned to be supported by the material3-adaptive library.

Building great games across surfaces

Gamers appreciate premium, immersive experiences and with Android tablets, foldables, desktops, and Chromebooks your game can reach more players than ever. Creating meaningful experiences on each of these devices is key to ensuring your game stands out.

Diablo Immortal saw significantly increased engagement across all aspects of the game by users who play on multiple devices.

During this year’s Google I/O, we are highlighting the best practices for rendering, managing assets, and windowing in resizable contexts to build quality experiences and impress your players across form factors.

With the wide variety of devices and hardware configurations, provide configurable graphics options for your players. And, for the best experience right out of the box, define default graphics options for different devices. Additionally, consider trade offs like storage size, performance, and compatibility across platforms when deciding what texture compression formats to use.

Large screen devices support different window sizes with configurations like multi-window mode and on orientation change and fold/unfold. By default, Android provides a compatibility mode - but, for the most seamless experience, declare and handle configuration events. Display cutouts, hinges, and even system UI can also occlude your game window, so support edge-to-edge windowing and ensure no key game content is occluded. If you really want to take your game to the next level, consider using the Jetpack WindowManager library to support dynamic layouts on foldable devices.

To provide smoother gameplay and reduce input latency consider using frame pacing. Also consider enabling wide color gamut support so that vivid colors are rendered properly while also maximizing contrast and brightness on large screen HDR displays to improve realism and immersion for your players.

With the changing mobile landscape and transition from OpenGL to Vulkan, handle swapchain recreation after window configuration changes. If you rely on any device specific hardware features like host visible device local memory have fallback implementations for other platforms.

Learn more about the rendering best practices and how to level up your game across surfaces by tuning into this technical session and be sure to check out our multiplatform optimization guide.

Get started building adaptable apps from phones to tablets and foldables

You can get started building adaptable apps that look great across tablets, foldables, Chromebooks and more by checking out the “Building adaptive Android apps” technical session or heading to the large screens gallery for content tailored to your specific app type - from productivity apps to games… and more!

Wear OS 4 is now stable and available on Google Pixel Watch 2!

Posted by Kseniia Shumelchyk, Android Developer Relations Engineer and Kevin Hufnagle, Android Technical Writer

Google Pixel Watch 2 is here and brings the capabilities of Wear OS 4 to users; get your app ready for the latest software and devices!


We're excited to bring Wear OS 4 and new user experiences to more devices, including the new Google Pixel Watch 2! We’re also providing updated developer tools for you to prepare your apps for Wear OS 4.

Pixel Watch 2, announced at Made by Google, will support Wear OS 4 upon its release this month. Wear OS 4 brings features and improvements to help you deliver more engaging and delightful experiences in your app.
Image of three watch faces created using the Watch Face Format

Later this year, Pixel Watches will receive a system update to Wear OS 4, further expanding the set of users who can enjoy your app’s capabilities on the latest software.

Developers can also continue to use Samsung Galaxy Watches to test their apps on Wear OS 4.

The latest version of Wear OS offers several capabilities that make it easier to develop dependable, helpful wearable experiences:

Watch Face Format

Created in partnership with Samsung, the Watch Face Format is a declarative XML format that lets you design the appearance and behavior of watch faces. There is no executable code involved in creating a watch face using the Watch Face Format, and there will be no code embedded in your watch face APK.

The Wear OS platform takes care of the logic needed to render the watch face that uses the Watch Face Format. This means that you don’t have to worry about code optimizations or battery performance. We recommend that you create your watch face using the Watch Face Format.

Image of three watch faces created using the Watch Face Format
Watch faces created using the Watch Face Format

More seamless data transfer

On devices that support cloud backup—including Pixel Watch 2 and Pixel Watch—users can transfer data from one Wear OS watch to another using a cloud backup and restore process. You can customize the set of files in your app that the system should include in a cloud backup, so that users only restore app data that’s meaningful to them.

Additionally, Wear OS 4 allows users to transfer their watch to a new phone without needing to perform a factory reset on the watch. They complete this process when setting up the new phone, as shown in the following flow below.

If your app stores user configuration data for the watch on the old phone, you can allow the system to transfer this app data onto the new phone too. The guide on how to transfer Wear OS data to a new mobile device has more details.

ALT TEXT
The user-facing process for transferring watch data onto a new phone, when the user first connects the new phone to the watch. This example shows the experience when the user initiates the data transfer from the old phone.

Enhanced Tiles

Wear OS 4 offers enhanced capabilities for your app’s tiles. Version 1.2 of the Jetpack Tiles library introduces support for platform data bindings and animations, so you can provide even more responsive experiences to your users.

Moving images of animated tile on the left and a tile using data binding on the right
Watch faces created using the Watch Face FormatExamples of animated tile (on the left) and a tile using data binding (on the right)

Get your app ready for Wear OS 4

Wear OS 4 is based on Android 13, which is several versions newer than the current Wear OS version, so your app will need to handle the system behavior changes that take effect in Android 12 and Android 13.

Read the developer documentation to discover key behavior changes and learn how to interact with new features. We recommend you start by testing your app and releasing a compatible update, so that you’re ready when the first devices get upgraded to Wear OS 4. This gives your app a basic but critical level of quality that provides a good experience for users.

Wear OS 4 emulator

Today we’ve also released updated system images for Wear OS emulators, available starting in Android Studio Hedgehog to help test your apps on Wear OS 4.

The new Wear OS 4 emulator doesn’t support native 32-bit code, so if your app uses native code, make sure that it includes both 32-bit and 64-bit native libraries. This will also prepare your app for upcoming 64-bit only hardware.

Learn more

To begin developing apps for Wear OS, try our Compose for Wear OS codelab, and check out the documentation and samples.

Discover even more! View the Wear OS session from Google I/O, and read about the latest Jetpack releases for Wear OS.

There’s never been a better time to get your app ready for Wear OS 4 and all the latest Wear OS watches. We can’t wait to see your apps on Wear OS 4 and what experiences you’ll build!

What’s new in the Jetpack Compose August ’23 release

Posted by Ben Trengrove, Android Developer Relations Engineer

Today, as part of the Compose August ‘23 Bill of Materials, we’re releasing version 1.5 of Jetpack Compose, Android's modern, native UI toolkit that is used by apps such as Play Store, Dropbox, and Airbnb. This release largely focuses on performance improvements, as major parts of our modifier refactor we began in the October ‘22 release are now merged.

Performance

When we first released Compose 1.0 in 2021, we were focused on getting the API surface right to provide a solid foundation to build on. We wanted a powerful and expressive API that was easy to use and stable so that developers could confidently use it in production. As we continue to improve the API, performance is our top priority, and in the August ‘23 release, we have landed many performance improvements.

Modifier performance

Modifiers see large performance improvements, up to 80% improvement to composition time, in this release. The best part is that, thanks to our work getting the API surface right in the first release, most apps will see these benefits just by upgrading to the August ‘23 release.

We have a suite of benchmarks that are used to monitor for regressions and to inform our investments in improving performance. After the initial 1.0 release of Compose, we began focusing on where we could make improvements. The benchmarks showed that we were spending more time than anticipated materializing modifiers. Modifiers make up the vast majority of a composition tree and, as such, were the largest contributor to initial composition time in Compose. Refactoring modifiers to a more efficient design began under the hood in the October ‘22 release.

The October ‘22 release included new APIs and performance improvements in our lowest level module, Compose UI. Modifiers build on top of each other so we started migrating our low level modifiers in Compose Foundation in the next release, March ‘23. This included graphicsLayer, low level focus modifiers, padding, and offset. These low level modifiers are used by other highly utilized modifiers such as Clickable, and are also utilized by many framework Composables such as Text. Migrating modifiers in the March ‘23 release brought performance improvements to those components, but the real gains would come when we could migrate the higher level modifiers and composables themselves to the new modifier system.

In the August ‘23 release, we have begun migrating the Clickable modifier to the new modifier system, bringing substantial improvements to composition time, in some cases up to 80%. This is especially relevant in lazy lists that contain clickable elements such as buttons. Modifier.indication, used by Clickable, is still in the process of being migrated, so we anticipate further gains to come in future releases.

As part of this work, we identified a use case for composed modifiers that wasn’t covered in the original refactor and added a new API to create Modifier.Node elements that consume CompositionLocal instances.

We are now working on documentation to guide you through migrating your own modifiers to the new Modifier.Node API. To get started right away, you can reference the samples in our repository.

Learn more about the rationale behind the changes in the Compose Modifiers deep dive talk from Android Dev Summit ‘22.

Memory

This release includes a number of improvements in memory usage. We have taken a hard look at allocations happening across different Compose APIs and have reduced the total allocations in a number of areas, especially in the graphics stack and vector resource loading. This not only reduces the memory footprint of Compose, but also directly improves performance, as we spend less time allocating memory and reduce garbage collection.

In addition, we fixed a memory leak when using ComposeView, which will benefit all apps but especially those that use multi-activity architecture or large amounts of View/Compose interop.

Text

BasicText has moved to a new rendering system backed by the modifier work, which has brought an average of gain of 22% to initial composition time and up to a 70% gain in one benchmark of complex layouts involving text.

A number of Text APIs have also been stabilized, including:

Improvements and fixes for core features

We have also shipped new features and improvements in our core APIs as well as stabilizing some APIs:

  • LazyStaggeredGrid is now stable.
  • Added asComposePaint API to replace toComposePaint as the returned object wraps the original android.graphics.Paint.
  • Added IntermediateMeasurePolicy to support lookahead in SubcomposeLayout.
  • Added onInterceptKeyBeforeSoftKeyboard modifier to intercept key events before the soft keyboard.

Get started!

We’re grateful for all of the bug reports and feature requests submitted to our issue tracker — they help us to improve Compose and build the APIs you need. Continue providing your feedback, and help us make Compose better!

Wondering what’s next? Check out our roadmap to see the features we’re currently thinking about and working on. We can’t wait to see what you build next!

Happy composing!

What’s new in Jetpack Compose

Posted by Jolanda Verhoef, Android Developer Relations Engineer

It has been almost two years since we launched the first stable version of Jetpack Compose, and since then, we’ve seen its adoption and feature set grow spectacularly. Whether you write an application for smartphones, foldables, tablets, ChromeOS devices, smartwatches, or TVs, Compose has got you covered! We recommend you to use Compose for all new Wear OS, phone and large-screen apps. With new tooling and library features, extended Material Design 3, large screen, and Wear OS support, and alpha versions of Compose for homescreen widgets and TV… This is an exciting time!

Compose in the community

In the last year, we’ve seen many companies investigating and choosing Compose to build new features and migrate screens in their production applications. 24% of the top 1000 apps on Google Play have already chosen to adopt Compose! For example, Dropbox engineers told us that they rewrote their search experience in Compose in just a few weeks, which was 40% less time than anticipated, and less than half the time it took the team to build the feature on iOS. They also shared that they were interested in adopting Compose “because of its first-class support for design systems and tooling support”. Our Google Drive team cut their development time nearly in half when using Compose combined with architecture improvements.

It’s great to see how these teams experience faster development cycles, and also feel their UI code is more testable. Inspired? Start by reading our guide How to Adopt Compose for your Team, which outlines how and where to start, and shows the areas of development where Compose can bring huge added value.


Library features & development

Since we released the first Compose Bill of Materials in October last year, we’ve been working on new features, bug fixes, performance improvements, and bringing Compose to everywhere you build UI: phones, tablets, foldables, watches, TV, and your home screen. You can find all changes in the May 2023 release and the latest alpha versions of the Compose libraries.

We’ve heard from you that performance is something you care about, and that it’s not always clear how to create performant Compose applications. We’re continuously improving the performance of Compose. For example, as of last October, we started migrating modifiers to a new and more efficient system, and we’re starting to see the results of that migration. For text alone, this work resulted in an average 22% performance gain that can be seen in the latest alpha release, and these improvements apply across the board. To get these benefits in your app, all you have to do is update your Compose version!

Text and TextField got many upgrades in the past months. Next to the performance improvements we already mentioned, Compose now supports the latest emoji version 🫶 and includes new text features such as outlining text, hyphenation support, and configuring line breaking behavior. Read more in the release notes of the compose-foundation and compose-ui libraries.

The new pager component allows you to horizontally or vertically flip through content, which is similar to ViewPager2 in Views. It allows deep customization options, making it possible to create visually stunning effects:

Moving image showing Hoizontal Pager composable
Choose a song using the HorizontalPager composable. Learn how to implement this and other fancy effects in Rebecca Franks' blog post.

The new flow layouts FlowRow and FlowColumn make it easy to arrange content in a vertical or horizontal flow, much like lines of text in a paragraph. They also enable dynamic sizing using weights to distribute the items across the container.

Image of search filters in a real estate app created with flow layouts
Using flow layouts to show the search filters in a real estate app

To learn more about the new features, performance improvements, and bug fixes, see the release notes of the latest stable and newest alpha release of the Compose libraries.

Tools

Developing your app using Jetpack Compose is much easier with the new and improved tools around it. We added tons of new features to Android Studio to improve your workflow and efficiency. Here are some highlights:

Android Studio Flamingo is the latest stable release, bringing you:

  • Project templates that use Compose and Material 3 by default, reflecting our recommended practices.
  • Material You dynamic colors in Compose previews to quickly see how your composable responds to differently colored wallpapers on a user device.
  • Compose functions in system traces when you use the System Trace profiler to help you understand which Compose functions are being recomposed.

Android Studio Giraffe is the latest beta release, containing features such as:

  • Live Edit, allowing you to quickly iterate on your code on emulator or physical device without rebuilding or redeploying your app.
  • Support for new animations APIs in Animation preview so you can debug any animations using animate*AsState, CrossFade, rememberInfiniteTransition, and AnimatedContent.
  • Compose Preview now supports live updates across multiple files, for example, if you make a change in your Theme.kt file, you can see all Previews updates automatically in your UI files.
  • Improving auto-complete behavior. For example, we now show icon previews when you’re adding Material icons, and we keep the @Composable annotation when running “Implement Members".

Android Studio Hedgehog contains canary features such as:

  • Showing Compose state information in the debugger. While debugging your app, the debugger will tell you exactly which parameters have “Changed” or have remained “Unchanged”, so you can more efficiently investigate the cause of the recomposition.
  • You can try out the new Studio Bot, an experimental AI powered conversational experience in Android Studio to help you generate code, fix issues, and learn about best practices, including all things Compose. This is an early experiment, but we would love for you to give it a try!
  • Emulator support for the newly announced Pixel Fold and Tablet Virtual Devices, so that you can test your Compose app before these devices launch later this year.
  • A new Espresso Device API that lets you apply rotation changes, folds, and other synchronous configuration changes to your virtual devices under test.

We’re also actively working on visual linting and accessibility checks for previews so you can automatically audit your Compose UI and check for issues across different screen sizes, and on multipreview templates to help you quickly add common sets of previews.

Material 3

Material 3 is the recommended design system for Android apps, and the latest 1.1 stable release adds a lot of great new features. We added new components like bottom sheets, date and time pickers, search bars, tooltips, and others. We also graduated many of the core components to stable, added more motion and interaction support, and included edge-to-edge support in many components. Watch this video to learn how to implement Material You in your app:


Extending Compose to more surfaces

We want Compose to be the programming model for UI wherever you run Android. This means including first-class support for large screens such as foldables and tablets and publishing libraries that make it possible to use Compose to write your homescreen widgets, smartwatch apps, and TV applications.

Large screen support

We’ve continued our efforts to make development for large screens easy when you use Compose. The pager and flow layouts that we released are common patterns on large screen devices. In addition, we added a new Compose library that lets you observe the device’s window size class so you can easily build adaptive UI.

When attaching a mouse to an Android device, Compose now correctly changes the mouse cursor to a caret when you hover the cursor over text fields or selectable text. This helps the user to understand what elements on screen they can interact with.

Moving image of Compose adjusting the mouse cursor to a caret when the mouse is hovering over text field

Glance

Today we publish the first beta version of the Jetpack Glance library! Glance lets you develop widgets optimized for Android phone, tablet, and foldable homescreens using Jetpack Compose. The library gives you the latest Android widget improvements out of the box, using Kotlin and Compose:

  • Glance simplifies the implementation of interactive widgets, so you can showcase your app’s top features, right on a user’s home screen.
  • Glance makes it easy to build responsive widgets that look great across form factors.
  • Glance enables faster UI Iteration with your designers, ensuring a high quality user experience.
Image of search filters in a real estate app created with flow layouts

Wear OS

We launched Compose for Wear OS 1.1 stable last December, and we’re working hard on the new 1.2 release which is currently in alpha. Here’s some of the highlights of the continuous improvements and new features that we are bringing to your wrist:

  • The placeholder and placeholderShimmer add elegant loading animations that can be used on chips and cards while content is loading.
  • expandableItems make it possible to fold long lists or long text, and only expand to show their full length upon user interaction.
  • Rotary input enhancements available in Horologist add intuitive snap and fling behaviors when a user is navigating lists with rotary input.
  • Android Studio now lets you preview multiple watch screen and text sizes while building a Compose app. Use the Annotations that we have added here.

Compose for TV

You can now build pixel perfect living room experiences with the alpha release of Compose for TV! With the new AndroidX TV library, you can apply all of the benefits of Compose to the unique requirements for Android TV. We worked closely with the community to build an intuitive API with powerful capabilities. Engineers from Soundcloud shared with us that “thanks to Compose for TV, we are able to reuse components and move much faster than the old Leanback View APIs would have ever allowed us to.” And Plex shared that “TV focus and scrolling support on Compose has greatly improved our developer productivity and app performance.”

Compose for TV comes with a variety of components such as ImmersiveList and Carousel that are specifically optimized for the living room experience. With just a few lines of code, you can create great TV UIs.

Moving image of TVLazyGrid on a screen

TvLazyColumn {   items(contentList) { content ->     TvLazyRow { items(content) { cardItem -> Card(cardItem) }   } }

Learn more about the release in this blog post, check out the “What’s new with TV and intro to Compose” talk, or see the TV documentation!

Compose support in other libraries

It’s great to see more and more internally and externally developed libraries add support for Compose. For example, loading pictures asynchronously can now be done with the GlideImage composable from the Glide library. And Google Maps released a library which makes it much easier to declaratively create your map implementations.

GoogleMap( //... ) { Marker( state = MarkerState(position = LatLng(-34, 151)), title = "Marker in Sydney" ) Marker( state = MarkerState(position = LatLng(35.66, 139.6)), title = "Marker in Tokyo" ) }

New and updated guidance

No matter where you are in your learning journey, we’ve got you covered! We added and revamped a lot of the guidance on Compose:

Happy Composing!

We hope you're as excited by these developments as we are! If you haven't started yet, it's time to learn Jetpack Compose and see how your team and development process can benefit from it. Get ready for improved velocity and productivity. Happy Composing!