Intent to Extend Experiment: Compute Pressure API

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Mandy, Arnaud

Dec 4, 2023, 1:59:22 PM12/4/23
to Abridged recipients

Contact emails,,,

Original I2E



Origin Trial


The Compute Pressure API offers high-level states that represent the pressure on the system. It allows the implementation to use the right underlying hardware metrics to ensure that users can take advantage of all the processing power available to them as long as the system is not under unmanageable stress. “Pressure” is a generic term by design – at the moment it is calculated based on CPU load, but future plans include using signals from temperature and battery status, for example.

We would like to extend the current Origin Trial from M120 to M123 (inclusive).

Blink component


Search tags

compute pressure

TAG review

spec review: wide review tracker:

TAG review status

Issues addressed

Chromium Trial Name


Origin Trial documentation link

Chromium Trial Name


Origin Trial documentation link


Interoperability and Compatibility

Gecko: No signal (

WebKit: Negative ( This issue has been taken into account:

Web developers: Positive (

Other signals:


WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

Motivation For Requesting Extension.

We propose extending the “Compute Pressure API” Origin Trial. We decided to extend the experiment based on feedback from users and a need for wider testing with 3rd-party Origin Trial tokens.

One of the features of this API is that it can provide data to iframe's, even cross-origin ones, under certain circumstances. That is due to the fact that many video conferencing services provide an SDK to their users based on embedding the 3rd party code via an iframe. It was reported that this didn't work with the current origin trial, unless both the SDK and the embedder ask for individual tokens, which is not scalable across a number of sites, limiting the usefulness of the origin trial.

It is now possible to use a third-party origin trial instead which makes it possible for providers of embedded content to try out a new feature across multiple sites. For this reason we are requesting an extension.

Furthermore, the specification has been modified to support workers in the privacy algorithms. The implementation will be merged to chromium for M122 and should also be evaluated by the API users.

Ongoing technical constraints

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Supported to Windows, Mac, Linux, ChromeOS.

Support on Android (incl. Android WebView) has been deprioritized as there is no current way to access the telemetry needed after Android 11, and the current partners we are engaging with have no need as they are using native solutions on Android at this point.

Is this feature fully tested by web-platform-tests?


DevTrial instructions

Flag name on chrome://flags


Finch feature name


Non-finch justification


Requires code in //chrome?


Tracking bug

Launch bug

Estimated milestones

 OriginTrial desktop last  (new request)     


OriginTrial desktop last


OriginTrial desktop first


OriginTrial desktop last


OriginTrial desktop first


DevTrial on desktop


Link to entry on the Chrome Platform Status

Links to previous Intent discussions

Intent to prototype: Ready for Trial:

Intent to Experiment:

Intent to Experiment:

Intent to Experiment:

Rick Byers

Dec 5, 2023, 2:20:47 PM12/5/23
to Mandy, Arnaud, Abridged recipients
Can you please request review for the security, privacy and debuggability bits now in the chromestatus tool? Perhaps there's some history somewhere you can point at from the first OT?

Otherwise, seems reasonable to extend to me.


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Chris Harrelson

Dec 6, 2023, 11:57:09 AM12/6/23
to Rick Byers, Mandy, Arnaud, Abridged recipients
On Tue, Dec 5, 2023 at 11:20 AM Rick Byers <> wrote:
Can you please request review for the security, privacy and debuggability bits now in the chromestatus tool? Perhaps there's some history somewhere you can point at from the first OT?

I think you also need to request API owners review, the intent isn't showing up properly in our dashboard.

Arnaud Mandy

Dec 7, 2023, 1:38:29 PM12/7/23
to blink-dev, Chris Harrelson, Arnaud Mandy, Abridged recipients,
@chris @rick, Thanks for the comments, it seems to be a new process.

We had gone through these privacy and security checks before, but not with the new chromestatus interface.

We've been requesting approval from privacy, security and also debuggability teams on chromestatus now.


Rick Byers

Dec 12, 2023, 10:27:59 AM12/12/23
to Arnaud Mandy, blink-dev, Chris Harrelson
Thanks, yeah the chromestatus UI is new so it's a little more formal now but not a new requirement. 

LGTM for API owners. But you'll need to confirm approval from security and privacy before extending the OT.

Arnaud Mandy

Dec 19, 2023, 4:18:23 AM12/19/23
to blink-dev,, blink-dev, Chris Harrelson, Arnaud Mandy

@chris @rick, I think we have, now, all the approvals in order.

Can we consider our "Intent to Extend Experiment" approved?


Mike Taylor

Dec 19, 2023, 10:37:31 AM12/19/23
to Arnaud Mandy, blink-dev,, Chris Harrelson

Rick Byers

Dec 19, 2023, 11:35:34 AM12/19/23
to Mike Taylor, Arnaud Mandy, blink-dev, Chris Harrelson
+1. Thanks Arnaud! 

Mandy, Arnaud

Dec 20, 2023, 2:42:14 AM12/20/23
to Rick Byers, Mike Taylor, blink-dev, Chris Harrelson

Thanks to you for pointing out the chromestatus UI, new feature and follow up!


From: Rick Byers <>
Sent: Tuesday, December 19, 2023 18:35
To: Mike Taylor <>
Cc: Mandy, Arnaud <>; blink-dev <>; Chris Harrelson <>
Subject: Re: [blink-dev] Intent to Extend Experiment: Compute Pressure API
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