Activate additional debugging tools, or try out new or experimental features.
Chrome flags are a way to activate browser features that are not available by default.
For example, Chrome wanted to allow users to try picture-in-picture video functionality, before rolling it out to everyone.
The feature was made available behind a flag, so any user to try it out and give feedback. The code and design were tested and polished based on the feedback, so now you can use picture-in-picture by default in Chrome—and it works really well.
Understand the risks
Most Chrome users will never need to use Chrome flags.
If you do set Chrome flags, you need to be careful. By activating or deactivating features, you could lose data or compromise your security or privacy—and features you toggle with a flag may stop working or be removed without notice.
If you're an enterprise IT admin, you should not use Chrome flags in production. You might want to take a look at enterprise policies instead.
...and proceed with caution
Having said all that, if you're a web developer who needs to try out new technology—or just a curious geek—then getting to know Chrome flags can be really worthwhile.
There are two ways to set Chrome flags:
- From the
- By opening Chrome from the command line in a terminal.
To set a flag from the
chrome://flags page in Chrome, you need to find the flag, toggle the setting
for the flag, then relaunch the browser.
For example, to activate Chrome's heads-up display for performance metrics:
Search for the feature.
Set the value to Enabled.
Now you can use the heads-up display that shows technical information about web page performance.
If you're a web developer, you may want to set flags by opening Chrome from the command line in a
terminal. You run the command to open Chrome, and add the flags you want to set. There are a lot
more Chrome settings you can configure from the command line than what's available on the
/Applications/Google\ Chrome\ Canary.app/Contents/MacOS/Google\ Chrome\ Canary
That's just one example! There are hundreds of other flags for activating, deactivating and configuring less well-known features.
Beware of flag conflicts
It's possible that the flags you set could conflict with each other. In particular, the defaults for
chrome://flags setting might, in some cases, override your command line configurations. So—if
the flags you set running Chrome from the command line don't work as expected, you should check your
Also be aware that
chrome://flags might not show the flag settings you've used from the
command line. Instead, take a look at
chrome://version. From the Command Line section,
you can check what flags are enabled in your browser.
This example matches the example above, that runs Chrome from the command line with flags.
Two other ways to try out experimental features
You can enable a range of experimental features that don't have their own flag, by toggling the
chrome://flags#enable-experimental-web-platform-features flag. Documentation for new features will
explain when this is an option.
Which features get a flag?
Not all experimental features get their own Chrome flag:
- Some features only become available when they ship in Chrome Canary, and can't be activated by a flag before that. This is quite rare.
- For 'smaller' features that require no more than 1–2 quarters of work, experimental availability
is provided by enabling the following flag:
This activates multiple minor features.
- Major features are made available for experimentation with flags specific to the feature, via
chrome://flagsor command line switches.
What about Chrome settings?
Chrome settings and Chrome flags serve different purposes.
Chrome flags enable the user to activate or deactivate experimental features, whereas the controls
available from the
chrome://settings page allow the user to customize their experience for features
that are available by default.
What about origin trials?
Origin trials are a way for developers to test a new or experimental web platform feature at scale, and give feedback to the web standards community before the feature is made available to all users.
Features undergoing an origin trial are activated on all pages that provide a valid token for that trial. This allow website owners to activate an experimental feature for all their users, without requiring users to change browser settings or set flags. By comparison, Chrome flags allow individual users to activate or deactivate an experimental feature, on all websites they visit. Getting started with Chrome's origin trials provides more detail.
Find out more
- The chromium.org website explains how to set flags from the command line, for mobile and desktop on different platforms.
- Learn about features, flags, switches, and other patterns for browser experimentation.
- Chrome Flags for Tooling documents flags relevant to tools, automation, and benchmarking.
- List of Chromium Command Line Switches is automatically updated with all available flags and, last time we checked, there were more than 1400 of them!
- Chromium Flag Updates is a bot that tweets changes to the chrome/browser/flag-metadata.json file.
- Experimental features in Firefox