System WebView Shell

WebView team maintains a “shell”--a thin interface over the WebView APIs--to exercise WebView functionality. The System WebView Shell (AKA “shell browser,” “WebView shell”) is a standalone app implemented in chromium. While often used for manual testing, we also use the shell for automated tests (see our layout and page cycler tests).

This relies on the WebView installed on the system. So if you're trying to verify local changes to WebView, or run against a specific WebView build, you must install WebView first.
Tip: the shell displays the WebView version (the corresponding chromium version number) in the title bar at the top. This can be helpful for checking which WebView version is installed & selected on the device.

Working with the shell

# Build and install
$ autoninja -C out/Default system_webview_shell_apk
$ out/Default/bin/system_webview_shell_apk install

# Launch a URL from the commandline, or open the app from the app launcher
$ out/Default/bin/system_webview_shell_apk launch ""

# For more commands:
$ out/Default/bin/system_webview_shell_apk --help
Note: system_webview_shell_apk does not support modifying CLI flags. See Instead, you should modify WebView's flags by following