Third-party origin trials

Providers of embedded content can test new or experimental web platform features.

Origin trials are a way to test a new or experimental web platform features with real users.

Origin trials are usually only available on a first-party basis. This means, the features only work on the registered origin. If a developer wants to test an experimental feature on other origins where their content is embedded, those origins all need to be registered for the origin trial, each with a unique trial token. This isn't a scalable approach for testing scripts that are embedded across a number of sites.

Third-party origin trials make it possible for providers of embedded content to try out a new feature across multiple sites by providing a token using JavaScript.

Third-party origin trials enable a single registration token to be used across multiple origins.

Third-party origin trials don't make sense for all features. Chrome only offers the third-party origin trial option for features where embedding code on third-party sites is a common use case.

If you're new to origin trials, start by reading Get started with Chrome origin trials.

If you participate in an origin trial as a third-party provider, it's your responsibility to notify and set expectations with any partners or customers whose sites you intend to include in the origin trial. Experimental features may cause unexpected issues and browser vendors may not be able to provide troubleshooting support.

Supporting third-party origin trials allows for broader participation.

Check Chrome Platform Status for updates on progress with third-party origin trials.

Register for a third-party origin trial

  1. Select an active trial.
  2. Register for the trial and, if available, enable the option to request a third-party token.

  3. For some trials, there are options for different usage restrictions when registering for a token. If available, select one of following to restrict usage for third-party tokens:

    1. Standard Limit: 0.5% of Chrome page loads.

    2. User Subset: A small percentage of Chrome users are excluded from the trial, even when a valid third-party token is provided. The exclusion percentage varies (or might not apply) for each trial, but is typically less than 5%.

  4. Click Register to submit your request.

  5. Your third-party token is issued immediately, unless further review of the request is required.

  6. If review is required, you'll be notified by email when the review is complete and your third-party token is ready.

    Chrome origin trials registration page for the Conversion Measurement API, with third-party matching checkbox selected.
    Registration page for the Conversion Measurement trial.

Provide a trial token programmatically

To take part in an origin trial, a page must provide a valid trial token. If you want a trial feature to be enabled on multiple sites where your code is embedded, use JavaScript to inject a token:

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

Otherwise, you would need to get every site that embeds your code to provide a token with an HTTP header or in their HTML.

Share feedback

If you're registering for a third-party origin trial and have feedback to share on the process or ideas on how we can improve it, create an Issue on GitHub.

Find out more