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Get started with origin trials | Web Platform | Chrome for Developers

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What are Origin Trials?

Origin trials allow developers to test experimental web platform features for a limited time. Participation is open to all developers and provides valuable feedback to the Chrome team. These trials are also available on Firefox and Microsoft Edge.

Availability and Participation

Origin trials are public, but participation is self-managed with limited support. Developers register for trials, receive tokens to enable features, and provide feedback. Some trials include third-party options and deprecation trials.

How to Participate

Participation involves:

Choosing an active trial.
Requesting a token.
Adding the token to your webpage via meta tag, HTTP header, or programmatically.
Testing the feature.
Submitting feedback.

Tokens are renewed periodically, requiring additional feedback. Instructions are also provided for using tokens with iframes and extensions.

Resources and Additional Information

The article includes links to additional documentation, troubleshooting guides, a token decoder tool, and example demos to further assist developers.

Get started with origin trials

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Test a new or experimental web platform feature.

Origin trials give you access to a new or experimental feature, so that you can test this feature and offer it to your users, for a limited time. Once the trial is completed and the feedback assessed, Chrome decides if the feature should be made available to everyone.

You can register for an origin trial to enable a feature for all users on your origin, without requiring them to toggle any flags or switch to an alternative build of Chrome (though, they may need to upgrade). Once, registered, developers can build demos and prototypes using the new features. The trials also help Chrome engineers understand how new features are used and how they may interact with other web technologies.

Availability

Origin trials are public and open to all developers. They are limited in duration and usage. Participation is a self-managed process with limited documentation and support. Participants should be willing and able to work relatively independently using the documentation available, which, at this stage, is likely limited to API specifications and explainers. We do try to provide guidance whenever possible.

If you register for a trial, the Chrome team will periodically ask you for specific feedback on your use of the trial feature. Some features may undergo multiple origin trials, as feedback is incorporated and adjustments are made.

Origin trials are also available for Firefox and Microsoft Edge.

Third-party origin trials

By default, an origin trial feature is only available on the origin registered for the trial. Some trials provide a Third-party matching option on registration. This allows providers of embedded content or services to try a new feature across multiple sites, without requiring a token for every origin.

Find out more: What are third-party origin trials?

Deprecation trials

Some origin trials allow you to temporarily re-enable a deprecated feature. These are known as deprecation trials. In some contexts, they are referred to as "reverse" origin trials.

For example, mutation events were removed, starting in Chrome 127. Sites that needed extra time before removing these events, can register for the deprecation trial to re-enable the events temporarily, on specified sites.

Take part in an origin trial

Choose an origin trial from the list of active trials.
Request a token by clicking the Register button and filling out the form.
Provide the token on every web page for which you want the trial feature to be enabled:
- As a meta tag in the <head>: <meta http-equiv="origin-trial" content="TOKEN_GOES_HERE">
- As an HTTP header: Origin-Trial: TOKEN_GOES_HERE
- By providing a token programmatically.
Try out the new feature.
Submit feedback. Do this through the origin trial site. This feedback is not public and is available only to a limited group of people on the Chrome team. Each trial also provides a link for spontaneous community feedback. This typically points to the feature on GitHub or some other public channel.
When your token expires, you will get an email with a renewal link. To do so, you are again asked to submit feedback.

You can register for the same origin trial multiple times, for different origins, and include multiple tokens in the same page. This can be useful if you need to provide tokens that are valid for resources served from different origins, such as code included on multiple sites that you own.

The origin trials framework looks for the first valid token and then ignores all other tokens. You can validate this with Chrome DevTools.

Provide a token programmatically

Instead of providing a token as an HTTP header or as a meta tag in the HTML of your page, as described earlier, you can inject a token with JavaScript:

const otMeta = document.createElement('meta'); otMeta.httpEquiv = 'origin-trial'; otMeta.content = 'TOKEN_GOES_HERE'; document.head.append(otMeta);

Use this method if you're participating in a third-party trial.

Caution: A third-party token must be provided in an external JavaScript file included with a <script> element. A third-party token won't work in a meta tag, inline script or HTTP header.

Tokens and iframes

To access a trial feature from an iframe, you can provide a trial token in a meta tag, an HTTP header, or programmatically.

As for all token usage, the origin registered for the token must match the context of JavaScript that accesses the trial feature: either the origin of the page the includes an inline script, or the src of a <script> element for JavaScript included from an external file.

Tokens and extensions

To use a trial feature inside of a background script, popup, sidepanel, or offscreen document, use the trial_tokens key in your manifest.json file.

"trial_tokens": ["AnlT7gRo/750gGKtoI/A3D2rL5yAQA9wISlLqHGE6vJQinPfk0HiIij5LhWs+iuB7mTeotXmEXkvdpOAC1YjAgAAAG97Im9yaWdpbiI6ImNocm9tZS1leHRlbnNpb246Ly9sampoamFha21uY2lib25uanBhb2dsYmhjamVvbGhrayIsImZlYXR1cmUiOiJJQ2Fubm90QmVsaWV2ZVlvdVdhc3RlZFlvdXJUaW1lRGVjb2RpbmdUaGlzIiwiZXhwaXJ5Ijo1NzI1NDA3OTk5fQ=="]

Content scripts are handled differently. Exposing a feature to one world could be confusing and unintuitive. Instead of using the manifest's trial_token, add the token to the page in one of the following ways:

Remember that tokens are tied to specific domains, so you need to register for the domain the content script is running on, rather than your extension ID.

To register your extension for a trial, you use the URL chrome-extension://YOUR_EXTENSION_ID, for example chrome-extension://ljjhjaakmncibonnjpaoglbhcjeolhkk.

Renew origin trial enrollment

If an origin trial is extended, you'll receive an email warning that you need to renew registration and provide a new token for each origin enrolled in the trial.

Go to My Registrations.
For each origin registered for the extended trial, click RENEW.
Copy the new token and make it available for every page that should remain enrolled in the trial. You can provide multiple tokens if necessary.