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How to Enable Experimental Web Platform Features in Chrome

How to turn on Chrome's experimental web platform features flag to test upcoming CSS and JavaScript APIs - and why you should never rely on it in production.

5 min read - Updated 2026-06-19

Chrome hides a flag that unlocks not-yet-shipped CSS and JavaScript features so you can test them before they roll out to users. Here is how to enable it safely, and the important caveat about relying on it.

Turning the flag on

Experimental web platform features live behind a chrome://flags entry. Enabling it exposes APIs that are implemented but not yet enabled by default, which is useful for previewing new CSS properties and browser APIs while they are still behind the flag.

Open chrome://flags in the address bar

Search for 'Experimental Web Platform features'

Set it to Enabled and relaunch Chrome

The same flag exists in Edge and other Chromium browsers

What it actually unlocks

The flag turns on features that have landed in Chromium but are still being stabilized - new CSS selectors, layout features, and JavaScript APIs that are weeks or months from default availability. It is a preview switch, not a settings menu, so the exact list changes with every Chrome version.

Upcoming CSS properties still being spec-finalized

New JavaScript and DOM APIs behind the flag

Behavior that can change or be removed between versions

Features that may never ship in their current form

Never rely on it for real users

This is the part people miss: the flag only affects your browser, and the features behind it are unstable. Anything you build on top of an experimental feature can break with the next update and will not work for visitors who have not flipped the flag. Use it to explore, then ship with proper feature detection and fallbacks.

Flagged features are off for your actual users

APIs can change shape or disappear between releases

Use @supports and feature detection for anything shipped

Treat it as a sandbox, not a deployment target

Release checklist

Enable the flag in chrome://flags and relaunch.

Confirm the specific feature you want is actually behind this flag.

Never ship code that depends on a flagged feature.

Add @supports fallbacks before using a new feature in production.

Frequently asked questions

How do I enable experimental web platform features in Chrome?

Open chrome://flags, search for 'Experimental Web Platform features', set it to Enabled, and relaunch Chrome. The same flag exists in Edge and other Chromium-based browsers.

Is it safe to enable experimental web platform features?

It is safe for testing on your own machine, but the features are unstable and can change or break between Chrome versions. Never build production code that depends on a flagged feature.

Will flagged features work for my site's visitors?

No. The flag only affects your own browser. Visitors who have not enabled it will not get the feature, so always use feature detection and fallbacks for anything you ship.

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