Checking out and building Chromium for Android

There are instructions for other platforms linked from the get the code page.

Instructions for Google Employees

Are you a Google employee? See go/building-chrome instead.

System requirements

  • A 64-bit Intel machine running Linux with at least 8GB of RAM. More than 16GB is highly recommended.
  • At least 100GB of free disk space.
  • You must have Git and Python installed already.

Most development is done on Ubuntu. Other distros may or may not work; see the Linux instructions for some suggestions.

Building the Android client on Windows or Mac is not supported and doesn't work.

Install depot_tools

Clone the depot_tools repository:

$ git clone

Add depot_tools to the end of your PATH (you will probably want to put this in your ~/.bashrc or ~/.zshrc). Assuming you cloned depot_tools to /path/to/depot_tools:

$ export PATH="$PATH:/path/to/depot_tools"

Get the code

Create a chromium directory for the checkout and change to it (you can call this whatever you like and put it wherever you like, as long as the full path has no spaces):

$ mkdir ~/chromium && cd ~/chromium
$ fetch --nohooks android

If you don't want the full repo history, you can save a lot of time by adding the --no-history flag to fetch.

Expect the command to take 30 minutes on even a fast connection, and many hours on slower ones.

If you've already installed the build dependencies on the machine (from another checkout, for example), you can omit the --nohooks flag and fetch will automatically execute gclient runhooks at the end.

When fetch completes, it will have created a hidden .gclient file and a directory called src in the working directory. The remaining instructions assume you have switched to the src directory:

$ cd src

Converting an existing Linux checkout

If you have an existing Linux checkout, you can add Android support by appending target_os = ['android'] to your .gclient file (in the directory above src):

$ echo "target_os = [ 'android' ]" >> ../.gclient

Then run gclient sync to pull the new Android dependencies:

$ gclient sync

(This is the only difference between fetch android and fetch chromium.)

Install additional build dependencies

Once you have checked out the code, run

$ build/

to get all of the dependencies you need to build on Linux, plus all of the Android-specific dependencies (you need some of the regular Linux dependencies because an Android build includes a bunch of the Linux tools and utilities).

Run the hooks

Once you've run install-build-deps at least once, you can now run the Chromium-specific hooks, which will download additional binaries and other things you might need:

$ gclient runhooks

Optional: You can also install API keys if you want your build to talk to some Google services, but this is not necessary for most development and testing purposes.

Configure the JDK

Make also sure that OpenJDK 1.7 is selected as default:

$ sudo update-alternatives --config javac
$ sudo update-alternatives --config java
$ sudo update-alternatives --config javaws
$ sudo update-alternatives --config javap
$ sudo update-alternatives --config jar
$ sudo update-alternatives --config jarsigner

Setting up the build

Chromium uses Ninja as its main build tool along with a tool called GN to generate .ninja files. You can create any number of build directories with different configurations. To create a build directory which builds Chrome for Android, run:

$ gn gen --args='target_os="android"' out/Default
  • You only have to run this once for each new build directory, Ninja will update the build files as needed.
  • You can replace Default with another name, but it should be a subdirectory of out.
  • For other build arguments, including release settings, see GN build configuration. The default will be a debug component build matching the current host operating system and CPU.
  • For more info on GN, run gn help on the command line or read the quick start guide.

Also be aware that some scripts (e.g., require you to set CHROMIUM_OUTPUT_DIR=out/Default.

Build Chromium

Build Chromium with Ninja using the command:

$ ninja -C out/Default chrome_public_apk

You can get a list of all of the other build targets from GN by running gn ls out/Default from the command line. To compile one, pass the GN label to Ninja with no preceding “//” (so, for //chrome/test:unit_tests use ninja -C out/Default chrome/test:unit_tests).

Installing and Running Chromium on a device

If the script below fails, make sure aapt is in your PATH. If not, add aapt's parent directory to your PATH environment variable (it should be /path/to/src/third_party/android_tools/sdk/build-tools/{latest_version}/).

Prepare the environment:

$ . build/android/

Plug in your Android device

Make sure your Android device is plugged in via USB, and USB Debugging is enabled.

To enable USB Debugging:

  • Navigate to Settings > About Phone > Build number
  • Click ‘Build number’ 7 times
  • Now navigate back to Settings > Developer Options
  • Enable ‘USB Debugging’ and follow the prompts

You may also be prompted to allow access to your PC once your device is plugged in.

You can check if the device is connected by running:

third_party/android_tools/sdk/platform-tools/adb devices

Which prints a list of connected devices. If not connected, try unplugging and reattaching your device.

Build the full browser

ninja -C out/Release chrome_public_apk

And deploy it to your Android device:

CHROMIUM_OUTPUT_DIR=$gndir build/android/ $gndir/apks/ChromePublic.apk # for gn.

The app will appear on the device as “Chromium”.

Build Content shell

Wraps the content module (but not the /chrome embedder). See for details on the content module and content shell.

ninja -C out/Release content_shell_apk
build/android/ out/Release/apks/ContentShell.apk

this will build and install an Android apk under out/Release/apks/ContentShell.apk. (Where Release is the name of your build directory.)

If you use custom out dir instead of standard out/ dir, use CHROMIUM_OUT_DIR env.

export CHROMIUM_OUT_DIR=out_android

Build WebView shell

Android WebView is a system framework component. Since Android KitKat, it is implemented using Chromium code (based off the content module). It is possible to test modifications to WebView using a simple test shell. The WebView shell is a view with a URL bar at the top (see code) and is independent of the WebView implementation in the Android system ( the WebView shell is essentially a standalone unbundled app). As drawback, the shell runs in non-production rendering mode only.

ninja -C out/Release android_webview_apk
build/android/ out/Release/apks/AndroidWebView.apk

If, instead, you want to build the complete Android WebView framework component and test the effect of your chromium changes in other Android app using the WebView, you should follow the Android AOSP + chromium WebView instructions


Set command line flags if necessary.

For Content shell:


For Chrome public:


For Android WebView shell:


Logging and debugging

Logging is often the easiest way to understand code flow. In C++ you can print log statements using the LOG macro or printf(). In Java, you can print log statements using android.util.Log:

Log.d("sometag", "Reticulating splines progress = " + progress);

You can see these log statements using adb logcat:

adb logcat...01-14 11:08:53.373 22693 23070 D sometag: Reticulating splines progress = 0.99

You can debug Java or C++ code. To debug C++ code, use one of the following commands:


See Debugging Chromium on Android for more on debugging, including how to debug Java code.


For information on running tests, see

Faster Edit/Deploy (GN only)

GN's “incremental install” uses reflection and side-loading to speed up the edit & deploy cycle (normally < 10 seconds). The initial launch of the apk will be a little slower since updated dex files are installed manually.

  • Make sure to setis_component_build = truein your GN args
  • All apk targets have *_incremental targets defined (e.g. chrome_public_apk_incremental) except for Webview and Monochrome

Here's an example:

ninja -C out/Default chrome_public_apk_incremental
out/Default/bin/install_chrome_public_apk_incremental -v

For gunit tests (note that run_*_incremental automatically add --fast-local-dev when calling

ninja -C out/Default base_unittests_incremental

For instrumentation tests:

ninja -C out/Default chrome_public_test_apk_incremental

To uninstall:

out/Default/bin/install_chrome_public_apk_incremental -v --uninstall

A subtly erroneous flow arises when you build a regular apk but install an incremental apk (e.g. ninja -C out/Default foo_apk && out/Default/bin/install_foo_apk_incremental). Setting incremental_apk_by_default = true in your GN args aliases regular targets as their incremental counterparts. With this arg set, the commands above become:

ninja -C out/Default chrome_public_apk

ninja -C out/Default base_unittests

ninja -C out/Default chrome_public_test_apk

If you want to build a non-incremental apk you'll need to remove incremental_apk_by_default from your GN args.

Tips, tricks, and troubleshooting

Rebuilding for a particular release

These instructions are only necessary for Chrome 51 and earlier.

In the case where you want to modify the native code for an existing release of Chrome for Android (v25+) you can do the following steps. Note that in order to get your changes into the official release, you'll need to send your change for a codereview using the regular process for committing code to chromium.

  1. Open Chrome on your Android device and visit chrome://version
  2. Copy down the id listed next to “Build ID:”
  3. Go to
  4. Download the listed files and follow the steps in the README.