This is not a thorough guide for how to build WebView, but is the fastest way to get a local build of WebView up and running.
Googlers should see internal instructions. External contributors should switch to a public (and finalized) Android release (there's no workaround).
See general Android instructions for:
depot_toolsIf you don‘t already have adb installed, the fastest way is to add chromium’s Android SDK to your $PATH. If you use multiple terminal, you'll want to run this command in each terminal:
$ source build/android/envsetup.sh
The recommend configuration is to use an Android 10 (Q) emulator. Android R or higher is also OK. If you need to use Android N-P instead then you can use the old version of this guide. If you need to use any other configuration, then you need to switch to the full build guide instead.
Set up an Android emulator. You have 2 options for this:
$ tools/android/avd/avd.py start \ --avd-config tools/android/avd/proto/generic_android29.textpb --emulator-window
Android Studio Emulator image. Install the Android Studio IDE and then follow these instructions to launch the Device Manager GUI. Create an emulator with these settings:
Once configured, click the play button to launch the emulator.
Verify your emulator is ready: after performing either of the steps above, you should check your emulator by running:
# If everything worked correctly, this should say "device" in the right column. $ adb devices List of devices attached emulator-5554 device
Configure GN args (run gn args out/Default) as follows:
target_os = "android" target_cpu = "x86" # Recommended: this lets you use System WebView Shell as a test app. system_webview_shell_package_name = "org.chromium.my_webview_shell"
# Build $ autoninja -C out/Default system_webview_apk # Install the APK $ out/Default/bin/system_webview_apk install # Tell Android platform to load a WebView implementation from this APK $ out/Default/bin/system_webview_apk set-webview-provider
That's it! Your APK should be installed and should be providing the WebView implementation for all apps on the system.
Skip this section if you already have an app you want to test.
You can start testing our your WebView APK with the System WebView Shell test app. This also shows the WebView version at the top of the app, so you can verify this is using the version you built locally. You can run this test app like so:
# Build $ autoninja -C out/Default system_webview_shell_apk # Install $ out/Default/bin/system_webview_shell_apk install # Launch a URL $ out/Default/bin/system_webview_shell_apk launch "https://www.google.com/"
For more info about WebView Shell, see the docs.
Skip this section if you don't need to toggle a specific commandline flag.
If you exposed your flag in ProductionSupportedFlagList.java, then you can toggle the flag in WebView DevTools. For more info about WebView DevTools, see the docs. You can launch WebView DevTools with:
$ adb shell am start -a "com.android.webview.SHOW_DEV_UI"
If the flag is not exposed, you can instead try following these steps.
We recommend starting with “printf-style debugging” on Android:
LOG(ERROR) << "SOMETAG: <your log message goes here>";org.chromium.base.Log.e("SOMETAG", "<your log message goes here>");system_webview_apk (see steps above). Re-launch your test app.adb logcat | grep 'SOMETAG'For more guidance, refer to the logging documentation.
We recommend starting with integration tests.
The recommended way to turn off your emulator is to just close the emulator window. If that doesn‘t work or you can’t find the emulator window, then you can safely shutdown your emulator by running adb emu kill in the terminal.
If the install command succeeded but something else is wrong, the best way to troubleshoot the problem is to query the state of the on-device WebViewUpdateService:
$ adb shell dumpsys webviewupdate Current WebView Update Service state Fallback logic enabled: true Current WebView package (name, version): (com.google.android.apps.chrome, 75.0.3741.0) Minimum WebView version code: 303012512 Number of relros started: 1 Number of relros finished: 1 WebView package dirty: false Any WebView package installed: true Preferred WebView package (name, version): (com.google.android.apps.chrome, 75.0.3741.0) WebView packages: Valid package com.android.chrome (versionName: 58.0.3029.125, versionCode: 303012512, targetSdkVersion: 26) is installed/enabled for all users Valid package com.google.android.webview (versionName: 58.0.3029.125, versionCode: 303012500, targetSdkVersion: 26) is NOT installed/enabled for all users Invalid package com.chrome.beta (versionName: 74.0.3729.23, versionCode: 372902311, targetSdkVersion: 28), reason: No WebView-library manifest flag Invalid package com.chrome.dev (versionName: 54.0.2840.98, versionCode: 284009811, targetSdkVersion: 24), reason: SDK version too low Invalid package com.chrome.canary (versionName: 75.0.3741.0, versionCode: 374100010, targetSdkVersion: 25), reason: SDK version too low Valid package com.google.android.apps.chrome (versionName: 75.0.3741.0, versionCode: 2, targetSdkVersion: 28) is installed/enabled for all users
This APK does not contain a WebView implementation. Make sure you're building system_webview_apk.
This shouldn't happen for userdebug builds. If it does, add this GN arg:
# Any number >= "Minimum WebView version code": android_override_version_code = "987654321"
The targetSdkVersion of your APK is too low (it must be >= the platform‘s API level). This shouldn’t happen for local builds using tip-of-tree chromium on public OS versions (see note).
This shouldn‘t happen for userdebug devices, and there’s no workaround for user devices. Make sure you have a userdebug device (you can check with adb shell getprop ro.build.type).
This is the correct state. If this is not the “preferred WebView package” or the “current WebView package”, call set-webview-implementation again.
This shouldn't happen for com.google.android.apps.chrome (the recommended package name). If you need to use a different package name, you may be able to workaround this by enabling “redundant packages” (adb shell cmd webviewupdate enable-redundant-packages), reinstalling, and running set-webview-provider again.
Otherwise, please reach out to the team.
Either your package didn‘t install (see below) or you chose a package name which is not eligible as a WebView provider for this device. Double-check the package name in your GN args. If you’re on AOSP (any OS level), choose "com.android.webview". If you‘re on L-M, choose "com.google.android.webview". In either case, you’ll likely need to remove the preinstalled WebView APK.
Check the “Current WebView package” in the dumpsys output. You're probably hitting one of the cases above.
Double check your emulator is Android 10 (Q) and that this is a Google APIs image. Double check your GN args to make sure you are not setting the system_webview_package_name argument (it's OK to set system_webview_shell_package_name, but the other arg should be the default value). If everything looks correct, try:
# Try uninstalling any WebView updates $ adb uninstall com.android.webview # If the uninstall command succeeded, then try installing your locally compiled # WebView again: $ out/Default/bin/system_webview_shell_apk install $ out/Default/bin/system_webview_shell_apk set-webview-provider
This could fail for an even wider variety of reasons than already listed. Please reach out to the team.
Try building Chromium. If that doesn't work, please reach out to the chromium team for general guidance. If system_webview_apk is the only troublesome target, please reach out to the WebView team (see previous section).
If apps using WebView crash with stack traces like the following:
AndroidRuntime: Shutting down VM
AndroidRuntime: FATAL EXCEPTION: main
AndroidRuntime: Process: org.chromium.webview_shell, PID: 6683
AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{org.chromium.webview_shell/org.chromium.webview_shell.WebViewBrowserActivity}: android.util.AndroidRuntimeException: java.lang.reflect.InvocationTargetException
...
AndroidRuntime: Caused by: android.util.AndroidRuntimeException: java.lang.reflect.InvocationTargetException
...
AndroidRuntime: Caused by: org.chromium.base.library_loader.ProcessInitException: errorCode=2
...
AndroidRuntime: Caused by: java.lang.UnsatisfiedLinkError: dlopen failed: library "libc++_chrome.so" not found
...
This UnsatisfiedLinkError can occur when WebView is built using the target_cpu = "x86" gn arg and the emulator architecture is x86_64. Double check your emulator is Android 10 (Q) and uses the x86 ABI.
Proceed at your own risk. Building and installing WebView is, for a variety of reasons, complex. If you‘ve deviated from any of these instructions (and don’t know what you‘re doing) there’s a good chance of making mistakes (some of which don't have any error messages).
If you can't follow the quick start guide for some reason, please consult our general build instructions. You can also try the old version of the quick start.