Intent to Extend Experiment: User-Agent Reduction Origin Trial

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Mike Taylor

Aug 2, 2022, 1:44:52 PM8/2/22
to blink-dev

Hi there,

We would like to extend the User-Agent Reduction OT again, from M104 to M106 (inclusive). The original extension expired on July 26th. We’ve heard from several partners that they would like to have more time to test the fully reduced UA string ahead of Phase 5 and Phase 6 rollouts. 

Original I2E 

First I2EE 

Experiment Timeline

M103-M106 inclusive

Reason this experiment is being extended

Like the previous extension, we believe the risks for burn-in don't apply, because this OT just enables what we are planning to ship as default behavior in the future (and the OT stopped working last week).

We still have not received negative feedback or reports of breaking from OT participants, and are encouraged by that fact.

Here’s the relevant info required for OT extensions beyond 6 milestones:

Draft spec: 

TAG review: requests

  • Gecko: Shipped/Shipping. Firefox has frozen (or capped) much of their UA string already.

  • WebKit: Shipped/Shipping. Safari has already frozen everything in their UA string except for version number info.

  • Web developers: Mixed signals. Reactions have ranged from positive to indifferent to negative, from various channels.

WPT tests

  • None yet, since UAs have flexibility to diverge here. With more alignment, this may make sense in the future.

Thanks, Mike

Chris Harrelson

Aug 3, 2022, 11:50:27 AM8/3/22
to Mike Taylor, blink-dev

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Victor Tan

Aug 9, 2022, 1:18:03 PM8/9/22
to blink-dev, Mike Taylor
The User-Agent Reduction Origin Trial is now live and will continue to work until Oct 18.


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