12L Developer Preview

Welcome to the 12L Preview, a program that gives you everything you need to make your apps compatible and build for the upcoming 12L feature drop for Android 12. The program is free, and you can get started right away by downloading the Preview SDK and tools.

Timeline, milestones, and updates

Timeline for the 12L developer previews and betas

The 12L Preview program runs from October 2021 until the final public release to AOSP, planned for early 2022. We'll deliver monthly updates for your development and testing environments. Each includes SDK tools, system images, docs and API reference, and API diffs. The program includes the following milestones:

Timeline Build Type Developer actions
October Developer Preview 1 Early baseline build focused on developer feedback, with a small number of new features, APIs, and behavior changes. Priority window for feedback on APIs. Explore new APIs and behavior changes and report any critical issues or requests to us during this time. Begin early app compatibility testing.
December Beta 1 Initial beta-quality release, over-the-air update to early adopters who enroll in Android Beta. Continue compatibility testing, watch for feedback from Android Beta users. Notify SDK and library developers of any issues.
January Beta 2 Final APIs Start final compatibility testing for apps, SDKs, and libraries. Release compatible versions. Compile apps against official API 32 SDK if needed.
February Beta 3 Incremental beta update Start final compatibility testing for apps, SDKs, and libraries. Release compatible versions. Compile apps against official API 32 SDK if needed.
Q1 2022 Final release 12L release to AOSP and ecosystem Release compatible updates for apps, SDKs, and libraries.

Preview phases

For developers, the focus during the Developer Preview phase is on API feedback and app compatibility. App compatibility means testing the current version of your app looks right and runs well on the new platform.

The Developer Preview builds provide an early test and development environment that you can use to try your app with the 12L features. Although we are not planning to add any breaking changes in this release, we still recommend testing your app to identify any potential compatibility issues so you can plan migration or feature work if necessary. It's especially important to give us your feedback during this time. You should also expect some API changes with each of these updates.

Beta 1 gives you a more complete and stable environment for building and testing the 12L features, and it's the first build that we deliver to early adopters who are enrolled in the Android Beta program. During the Beta releases period, early adopters will be using your app on Pixel devices, so we recommend watching for feedback from those users and releasing compatible updates to address any issues, without changing the app's targeting.

Starting at Beta 2, system behaviors and APIs are finalized. This is the time to begin final testing and development work needed to ensure that a compatible version of your app will be ready for users getting this update. 12L will have a standard API level (API level 32) at this time.

With the final APIs, it's also time to shift focus to final compatibility testing and release your updated apps to users and downstream developers. You can also build with the final APIs and refine any new code that is using the new APIs or features.

12L API Level and optional platform targeting

The 12L update includes a small number of new APIs for developers. While the APIs are still in development, the 12L platform uses the provisional API level "Sv2". When the APIs are finalized, the 12L platform will use the API level "32".

For developers it will be optional (but recommended) for apps to target the 12L API level (targetSdkVersion="32") to meet Google Play requirements. For details on the latest Google Play targeting requirements, see this article.

What's included in the 12L Preview?

The 12L Preview program includes everything you need to test your existing apps on a variety of screen sizes, network technologies, CPU and GPU chipsets, and hardware architectures.

SDK & tools

Using Android Studio, you can download the following components through the SDK Manager:

  • 12L SDK and tools
  • 12L emulator system image for all screen sizes (64-bit only, see release notes)

We'll provide updates to these development tools at each milestone as needed.

See Get 12L to get started. See the release notes for known issues.

Emulator and Pixel system images

Most of the changes in 12L are designed for large screen devices, so they won't be visible on smaller screen devices like phones. To give you a runtime environment to try the new features, we're providing a 12L emulator that you can use with any emulator device configuration supported by Android Studio Bumblebee Beta 3 or later.

During the Preview, we strongly recommend testing your app using the 12L emulator with a tablet, foldable, or desktop device configuration.

See Get 12L for details on how to set up the 12L emulator.

As a secondary goal, it's also good to test for compatibility on phones, since they will also be getting 12L. Starting at Beta 1, we'll provide system images for all supported Pixel devices, as well as GSI images for broader device support for your development and testing. Visit the downloads page at that time to get a system image for development and testing.

OTA updates for Pixel through the Android Beta program

Starting at Beta 1, if you have one of the following Google Pixel devices, you can enroll the device in the Android Beta for Pixel program to get over-the-air (OTA) updates to 12L milestones:

  • Pixel 6 Pro
  • Pixel 6
  • Pixel 5a with 5G
  • Pixel 5
  • Pixel 4a (5G)
  • Pixel 4a
  • Pixel 4
  • Pixel 3a XL
  • Pixel 3a

Once enrolled, your device will receive regular OTA updates through (and including) the 12L final release.

Once enrollment is available, visit g.co/androidbeta to enroll.

Preview APIs and publishing

The 12L Preview initially provides a development-only system and Android library that does not have a standard API level. If you want to target the new platform and build with the new 12L APIs during this time, you must target the Preview version of 12L by setting your app's targetSdkVersion and minSdkVersion to "Sv2" and its Gradle compileSdkVersion to "Sv2". For more information, see Update your build configuration for 12L.

The 12L Preview delivers preview APIs—the APIs are not official until the final SDK is released. This means that you can expect API changes over time, especially during the Developer Preview phase of the program. We'll provide a summary of changes with each 12L release.

At Beta 2, developer APIs will be finalized and you'll be able to download the official 12L SDK into Android Studio, target the official API level, 32, and compile against the official APIs. Note that apps compiled against preview versions of the SDK won't be installable on system images that support the final APIs.

Until the APIs are finalized, Google Play prevents publishing of apps that target Sv2. When the final SDK is available, you can then target the official 12L API level and publish your app to Google Play using the alpha, beta, and production release channels. Meanwhile, if you want to distribute an app to testers that targets 12L, you can do so through email or by direct download from your site at any time.

Stay up to date

Throughout the 12L Preview, as you test on Developer Preview and Beta releases, we strongly recommend keeping your development environment up-to-date. We'll notify you when new updates are available using the following channels:

More information

To learn more about 12L, see the following documentation resources:

  • The 12L features and changes page summarizes all of the documented features and behavior changes that might affect app developers.
  • The release notes page lists and describes known issues and transitive changes that are specific to each Developer Preview or Beta release.

API Reference and diff report

The full 12L API reference is available online. When the new APIs are under development, they are watermarked for visibility and show "Sv2" as the API level. Note that you can only use these APIs if you are building with the 12L Preview SDK.

When the official 12L SDK is available, the API reference marks new APIs with the official API level, 32.

For a detailed view of new, modified, deprecated, and removed APIs in each release, we recommend starting with the diff reports listed in the release notes.

Changes in the diff reports contain links to related API reference documentation.

Support resources

As you test and develop with 12L, use these channels to report issues and give feedback:

  • Visit the Feedback and issues page for complete information on how to report issues and let us know what you think.

  • The Developer Preview issue tracker is our primary issue tracker. You can report bugs, performance issues, and general feedback through the issue tracker. You can also check for known issues and find workaround steps. We'll keep you updated on your issue as it's triaged and sent to the Android engineering team for review. For details on how to report various kinds of issues, see the Where to report issues section.

  • The Android Beta Community is a community where you can connect with other users and developers who are working with the 12L Beta. You can share observations and ideas and find answers to questions there.

Get started!

To get started, set up an emulator for compatibility testing by following the steps in Get 12L. Optimize your app for large screens to create a better experience for your users today. Thank you for participating in the 12L Preview program!