Welcome to the Android Open Source Project!

Android is an open source software stack for a wide range of mobile devices and a corresponding open source project led by Google. This site and the Android Open Source Project (AOSP) repository offer the information and source code you need to create custom variants of the Android stack, port devices and accessories to the Android platform, and ensure your devices meet compatibility requirements.

Android 7.1 Updates Available

What's New

Android Security 2016 Year in Review

The Android Security team has published its 2016 Year In Review.

March Android Security Bulletin

The March 2017 Android Security Bulletin has been published along with links to associated fixes. In addition, new build numbers have been published for Nexus 6 running Android 7.0 and 7.1.1 and also Pixel, Pixel XL, Pixel C, Nexus 5X, Nexus 6P, Nexus 9, and Nexus Player running Android 7.1.1 to support the March Android security release.

Systems Testing With VTS

The Vendor Test Suite (VTS) automates HAL and OS kernel testing. New documentation covers how to use VTS to test an Android native system implementation, set up a testing environment then test a patch using a VTS plan.

New Dalvik Bytecodes and Formats

Dalvik now offers new bytecode formats 45cc and 4rcc and placeholder opcodes for invoke-polymorphic and invoke-polymorphic/range, which are the first dex instructions that use these new formats. In addition to a method_idx that gives the invoked method, these instructions also provide a proto_idx that gives the (static) type signature of the call site.

Background App Compilation in A/B System Updates

Examples for installing and configuring otapreopt_script have been added to explain how to use this tool for optimizing user apps so they are ready to run after the device reboots during an A/B system update.

Android 7.1 CDD

The 7.1 version of the Android Compatibility Definition Document (CDD) has been published. See its change log for a summary of updates.

Getting Started

Explore the Source

Get the complete Android platform and modify and build it to suit your needs. You can also contribute to the AOSP repository to make your changes available to everyone else in the Android ecosystem.

Android framework summary

Port Android to Devices

Get help porting the latest Android platform to create compelling devices for your customers. Includes documentation for HAL interfaces and details on core technologies such as Android runtime (ART) and over-the-air (OTA) updates.

Make Secure

Follow these examples and instructions to harden your Android devices against malicious attacks. Find out how the Android security program works and learn how to implement the latest features.

Get Compatible

Being Android-compatible lets you offer custom features but still give users and developers a consistent and standard experience across all Android-powered devices. Android provides guidance and a test suite to verify your Android compatibility.

Help this Site

Use the Site Feedback button at the bottom of any page to request content improvements or let us know about errors. To contribute your own updates to the site or to view a complete list of site changes, use the AOSP project docs/source.android.com.