Before you download and build the Android source, ensure that your system meets the following requirements, then see Establishing a Build Environment for installation instructions by operating system.

Hardware requirements

Your development workstation should meet or exceed these hardware requirements:

  • A 64-bit environment is required for Android 2.3.x (Gingerbread) and higher versions, including the master branch. You can compile older versions on 32-bit systems.
  • At least 250GB of free disk space to check out the code and an extra 150 GB to build it. If you conduct multiple builds, you need additional space.
  • At least 16 GB of available RAM is required, but Google recommends 64 GB.

As of June 2021, Google is using 72-core machines with 64 GB of RAM internally, which take about 40 minutes for a full build (and just a few minutes for incremental builds, depending on exactly which files were modified). By contrast, a 6-core machine with a similar amount of RAM takes 3 hours.

Software requirements

The AOSP master branch is traditionally developed and tested on Ubuntu Long Term Support (LTS) releases, but other distributions may be used. See Establishing a Build Environment for additional required packages and the commands to install them.

Your workstation must have the software listed below. These requirements apply to the AOSP master branch. For Android versions 8.0 (Oreo or O) through 5.0 (Lollipop or L), consider using the included Dockerfile to ease installation of all required packages. For the manual method, see Supporting Older Versions.


If you're developing against the AOSP master branch, use Ubuntu 18.04 (Bionic Beaver).


The master branch of Android in AOSP comes with a prebuilt version of OpenJDK, so no additional installation is required.

Older versions of Android require a separate installation of the JDK. On Ubuntu, use OpenJDK.

Key packages

The AOSP master branch comes with a prebuilt version of Make, so no additional installation is required. Git is similarly installed as part of the Establishing a Build Environment process.

Ensure that your system has Python 3.

Device binaries

Download previews, factory images, drivers, over-the-air (OTA) updates, and other blobs below. For details, see Obtaining proprietary binaries.

Build toolchain

Android 8.0 and higher support only Clang/LLVM for building the Android platform. Join the android-llvm group to pose questions and get help. Report NDK/compiler issues at the NDK GitHub.

For the Native Development Kit (NDK) and legacy kernels, GCC 4.9 included in the AOSP master branch (under prebuilts/) may also be used.