Intent to Experiment: SoftNavigation performance entry

Skip to first unread message

Yoav Weiss

Nov 30, 2022, 9:01:46 AM11/30/22
to blink-dev

Contact emails



Not yet. I want to use the OT's feedback to assess the solution's viability.


Exposes the (experimental) soft navigation heuristics to web developers, using both PerformanceObserver and the performance timeline.

Blink component


TAG review

Not yet.

TAG review status

Not yet.


Interoperability and Compatibility

Gecko: No signal for now. Will file once feedback confirms viability.

WebKit: No signal for now. Will file once feedback confirms viability.

Web developers: Strong support!

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?


Goals for experimentation

I'm interested in gaining insights on the quality of the heuristic and how it compares to current heuristics employed by RUM providers or driven by framework- or app-specific knowledge. I'm also interested in knowing if developers find the correlation of various performance entries to their soft navigation ergonomic, and whether the emitted FP/FCP/LCP entries work well for them to evaluate the performance of their soft navigations.

Reason this experiment is being extended


Ongoing technical constraints



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


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


Flag name


Requires code in //chrome?


Tracking bug

Estimated milestones

OriginTrial desktop last112
OriginTrial desktop first109
OriginTrial Android last112
OriginTrial Android first109
OriginTrial webView last112
OriginTrial webView first109

Link to entry on the Chrome Platform Status

Links to previous Intent discussions

Intent to prototype:

This intent message was generated by Chrome Platform Status.

Mike Taylor

Nov 30, 2022, 9:16:26 AM11/30/22
to Yoav Weiss, blink-dev
LGTM to experiment from M109 to M112.
You received this message because you are subscribed to the Google Groups "blink-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
To view this discussion on the web visit

Yoav Weiss

Jan 6, 2023, 5:14:11 AMJan 6
to Mike Taylor, blink-dev
Update: We're bumping the experimentation from M109 to M110 (till M113), to align with partner timelines (and avoid them rediscovering bugs fixed in M109).
Reply all
Reply to author
0 new messages