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Run Chromium with flags

Contents

  1. 1 Windows
  2. 2 macOS
  3. 3 Linux
  4. 4 iOS
  5. 5 V8 Flags
  6. 6 Android
    1. 6.1 ContentShell on Android
    2. 6.2 Android WebView
  7. 7 Chrome OS

There are command line flags (or "switches") that Chromium (and Chrome) accept in order to enable particular features or modify otherwise default functionality.

Current switches may be found at http://peter.sh/examples/?/chromium-switches.html

It is important to note that some switches are intended for development and temporary cases. They may break, change, or be removed in the future without notice. IT admins looking to manage Chrome for their organization should instead use enterprise policies. 

Note that if you look at chrome://flags to see if the command line option is active, the state might not be accurately reflected. Check chrome://version for the complete command line used in the current instance.

Windows

  1. Exit any running-instance of Chrome.
  2. Right click on your "Chrome" shortcut.
  3. Choose properties.
  4. At the end of your "Target:" line add the command line flags. For example:
    • --disable-gpu-vsync
  5. With that example flag, it should look like below (replacing "--disable-gpu-vsync" with any other command line flags you want to use):
    chrome.exe --disable-gpu-vsync
  6. Launch Chrome like normal with the shortcut.

macOS

  1. Quit any running instance of Chrome.
  2. Run your favorite Terminal application.
  3. In the terminal, run commands like below (replacing "--remote-debugging-port=9222" with any other command line flags you want to use):
    /Applications/Chromium.app/Contents/MacOS/Chromium --remote-debugging-port=9222

    # For Google Chrome you'll need to escape spaces like so:
    /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222

Linux

  1. Quit any running instance of Chrome.
  2. Run your favorite terminal emulator.
  3. In the terminal, run commands like below (replacing "--remote-debugging-port=9222" with any other command line flags you want to use):
    chromium-browser --remote-debugging-port=9222
    google-chrome --foo --bar=2

iOS

If you are building Chromium from the source, you can run it with flags by adding them in the Experimental Settings.
  1. Open the Settings app
  2. Go to Chromium/Experimental Settings
  3. Add your flags in the "Extra flags (one per line)". Don't forget to switch on the "Append Extra Flags" setting.
It is not possible to run with flags the official releases (Google Chrome from App Store or Testflight).

V8 Flags

V8 can take a number of flags as well, via Chrome's js-flags flag. For example, this traces V8 optimizations:

chrome.exe --js-flags="--trace-opt --trace-deopt --trace-bailout"

To get a listing of all possible V8 flags:

chrome.exe --js-flags="--help"

Browse the V8 wiki for more flags for V8.

Android

Visit 'about:version' to review the flags that are effective in the app. 

If you are running on a rooted device or using a debug build of Chromium, then you can set flags like so:

out/Default/bin/chrome_public_apk argv  # Show existing flags.
out/Default/bin/content_shell_apk argv --args='--foo --bar'  # Set new flags

You can also install, set flags, and launch with a single command:

out/Default/bin/chrome_public_apk run --args='--foo --bar'
out/Default/bin/content_shell_apk run  # Clears any existing flags

For production build on a non-rooted device, you need to enable "Enable command line on non-rooted devices" in chrome://flags, then set command line in /data/local/tmp/chrome-command-line. When doing that, mind that the first command line item should be a "_" (underscore) followed by the ones you actually need. Finally, manually restart Chrome ("Relaunch" from chrome://flags page might no be enough to trigger reading this file). See https://crbug.com/784947.

ContentShell on Android

There's an alternative method for setting flags with ContentShell that doesn't require building yourself:

  1. Download a LKGR build of Android.
  2. This will include both ChromePublic.apk and ContentShell.apk
  3. Install ContentShell APK to your device.
  4. Run this magic incantation
adb shell am start \
  -a android.intent.action.VIEW \
  -n org.chromium.content_shell_apk/.ContentShellActivity \
  --es activeUrl "http://chromium.org" \
  --esa commandLineArgs --show-paint-rects,--show-property-changed-rects

This will launch contentshell with the supplied flags. You can apply whatever commandLineArgs you want in that syntax.

Android WebView

This is documented in the chromium tree.

Chrome OS

  1. Put the device into dev mode, disable rootfs verification, and bring up a command prompt.
  2. Modify /etc/chrome_dev.conf (read the comments in the file for more details).
  3. Restart the UI via:
    sudo restart ui
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