12L features and changes

The 12L feature drop makes Android 12 even better on large
screens

12L is a special feature drop that makes Android 12 even better on large screens. We've optimized and polished the system UI for large screens, made multitasking more powerful and intuitive, and improved our compatibility support for apps so they look better by default. We've also added a handful of developer APIs.

We plan to release 12L in a feature drop in early 2022, in time for the next wave of Android 12 tablets, Chromebooks, and foldables. With these features coming to devices in the months ahead, now is a great time to get your apps ready. You can get started by downloading the 12L emulator or by getting 12L on a partner device.

Here's a look at what's new.

An OS optimized for large screens

12L refines the system UI to make it more beautiful and easier to use on large screens—across notifications, quick settings, lockscreen, overview, the home screen, and more.

On large screens, the notification shade takes advantage of the space by showing Quick Settings and notifications in a new two-column layout. The lock screen also uses a larger two-column layout to highlight notifications and clock, and system apps like Settings are also optimized.

Large screen layouts display more content in a two-column layout.

We also focused on making key interactions easier on larger screens. For example, the lock screen pattern and PIN controls on tablets are now displayed at the side of the screen for easier reach, and users can simply tap the other side of the screen to bring the pin/pattern controls over to that side.

For foldables, we optimized the home screen grid and polished the fold-unfold transition, so that users move seamlessly from a single exterior screen to the larger unfolded screen, reinforcing continuity while preserving their choices.

For developers: Change in media projection

Starting in 12L, when the virtual display is rendered on the surface, the virtual display is scaled to fit the surface using a process similar to the centerInside option of ImageView.

The new scaling approach improves screen casting to televisions and other large displays by maximizing the size of the surface image while ensuring the proper aspect ratio.

For more details, see Media projection on large screens.

Powerful and intuitive multitasking

Users often multitask when using the larger screens of tablets, Chromebooks, and foldables. In 12L, new productivity features make multitasking even more powerful and intuitive.

12L adds a new taskbar that makes it easier to launch and switch apps on the fly. Gestures make using the taskbar even faster, with drag and drop to enter split-screen mode and swipe up to go home. In gesture navigation, a quick-switch gesture lets users flip through recent apps. Users can reveal or hide the taskbar at any time with a long press.

The taskbar lets users launch and switch apps faster, drag and drop to enter split-screen mode, and swipe up to go back home.

Running apps in split-screen mode is a popular way of multitasking, and in 12L we've made split screen easier than ever to discover and use. Users can now drag and drop their favorite apps into split screen directly from the taskbar, or they can also use a new "Split" action in the overview to start split-screen mode with a tap.

To make split screen a more consistent experience for users, Android 12 and higher allows all apps to enter multi-window mode, regardless of whether they are resizable.

For developers: Test your apps in split-screen mode

With split-screen mode becoming more accessible, and with the change in Android 12 that lets users launch all apps into split-screen, we strongly recommend that you test your apps in split-screen mode.

Improved compatibility experience

Many apps are already optimized for large screen devices and offer great experiences through responsive layouts, support for multi-window mode, continuity across screen size and device posture changes, and more.

For apps that are not yet optimized, we've made visual and stability improvements to our compatibility mode to provide a better experience for users and make those apps look better by default.

Compatibility mode improvements provide a better user experience for apps that are not optimized for large screens.

We improved the UI for letterboxing by making a number of options customizable by device manufacturers through overlay configurations. For example, device manufacturers can now configure the app aspect ratio, apply rounded corners to the app window, and set the status bar transparency.

For developers: Check your apps in compatibility mode

If your app isn't yet optimized to adapt to screen size and device posture changes, your app may be launched in compatibility mode. We recommend testing your app with 12L compatibility modes to make sure your app looks and functions properly.

For more details, see Enhanced letterboxing.

More updates and resources for large screens

Changes to Google Play on large screens

To make it easier for people to find the best app experiences on their tablets, foldables, and Chrome OS devices, we're making changes in Play to highlight apps that are optimized for their devices.

We’re adding new checks to assess each app’s quality against our large screen app quality guidelines to ensure that we surface the best possible apps on those devices. For apps that are not optimized for large screens, we’ll start warning large screen users with a notice on the app’s Play Store listing page.

We'll also be introducing large-screen-specific app ratings, as announced earlier in 2021, so users will be able to rate how your app works on their large screen devices.

These changes are coming in 2022, so we're giving you time to get your apps ready.

Activity embedding with Jetpack WindowManager

Activity embedding lets you take advantage of the extra display area of large screens by showing multiple activities at once, such as for the List-Detail pattern, and it requires little or no refactoring of your app. You determine how your app displays its activities—side by side or stacked—by creating an XML configuration file or making Jetpack WindowManager API calls. The system handles the rest, determining the presentation based on the configuration you’ve created. If your app uses multiple activities, we recommend giving activity embedding a try. To learn more, see Activity embedding.

Device orientation request

Unlike standard phones, foldables and tablets are frequently used in both landscape and portrait orientations. Tablets are often docked in landscape position, while foldables can be oriented based on their fold.

Some apps request a fixed orientation in portrait or landscape and expect to remain in their preferred orientation regardless of the orientation of the device (see the screenOrientation manifest attribute). While this is still supported in 12L, we’re now giving device manufacturers the option of overriding the app’s request for a preferred orientation.

In Android 12 (API level 31) and higher, device manufacturers can configure individual device screens (such as the tablet-size screen of a foldable) to ignore the orientation specification and force an app in portrait mode to be presented upright but letterboxed on landscape displays. By ignoring the specification, Android can better serve the developer’s intention of always presenting an app in a fixed aspect ratio while keeping the app oriented for optimal usability.

However, for the best user experience, design your apps with responsive layouts that make full use of the screen space available in both portrait and landscape orientations on screens larger than 600dp.

Get your apps ready

With the 12L feature drop coming to large screen devices in early 2022, now is the time to try your apps for the new features and give us feedback.

You can get started by setting up the 12L emulator. You'll be able to see the latest system UI changes for large screens, try your apps with the taskbar and split screen mode, test your app in compatibility mode, and even try activity embedding with the Jetpack WindowManager APIs.

Use the new resizable device definition for the Android Emulator to test 12L with variety of large screen scenarios.

If you're just getting started with large screens development, check out Large Screens and Foldables guides to read the latest guidance and techniques for building great experiences on these devices. Watch for regular updates coming your way throughout the 12L Developer Preview.

You can check out the timeline and learn more about the Preview program on the Program overview and timeline page.

What to test

After creating virtual devices for 12L, you'll want to test your app with some common large screen use cases to make sure that your app responds how you want. Here are a few recommended areas, with links to more details about related resources that can help you optimize your app for large screens:

What to test Resources
Screen sizes, device posture, and rotation

Check how your app responds when the size of the screen changes due to device posture changes (such as unfolding a foldable device or putting a foldable device in tabletop mode). Also try rotating the device in each of these states to ensure that your app responds optimally.

Documentation Samples Codelabs Technical talks
Taskbar interaction and split-screen mode

Check how your app responds when viewed with the taskbar on large screens. Check that your app's UI isn't cut off or blocked by the taskbar, try entering and exiting split-screen and multi-window modes using the taskbar, and test quickly switching between your app and other apps using the taskbar.

If your app has a fixed orientation and is not resizable, check how your app responds to compatibility mode adjustments such as letterboxing.

Documentation Samples Technical talks
Multi-window mode

Check how your app responds when running in multi-window mode on large screens (sw >= 600dp), especially if your app sets resizeableActivity="false".

If your app sets resizeableActivity="true", also be sure to check how your app responds when running in multi-window mode on small screens (sw < 600dp).

If your app uses Display APIs such as Display.getRealSize() and Display.getRealMetrics(), use the WindowMetrics APIs in the Jetpack WindowManager library instead.

Documentation Samples Technical talks
Media projection

If your app uses media projection, check how your app responds while playing back, streaming, or casting media on large screen devices. Be sure to account for device posture changes on foldable devices as well.

Documentation Samples Technical talks
Camera preview

For camera apps, check how your camera preview UI responds on large screens when your app is constrained to a portion of the screen in multi-window or split-screen mode. Also check how your app responds when a foldable device's posture changes.

Documentation