NavigationTiming - NotRestoredReasons

[yoavweiss]

Description

The NotRestoredReasons interface of the Performance API provides report data containing reasons why the current document was blocked from using the back/forward cache (bfcache) on navigation.

Specification

https://html.spec.whatwg.org/multipage/browsing-the-web.html#document-state-not-restored-reasons

web-feature

https://web-platform-dx.github.io/web-features-explorer/features/bfcache-blocking-reasons/

Test Links

https://wpt.fyi/results/performance-timeline/not-restored-reasons?label=experimental&label=master&aligned

Additional Signals

Positive Mozilla position: mozilla/standards-positions#766
No official WebKit position: WebKit/standards-positions#154

The feature would enable developers to understand why their sites are not being stored in the BFCache across browsers, enabling them to make their back/forward navigations faster.

[github-actions]

This comment was automatically generated based on the information you provided. Please don't edit it.

No web features (from the web-features project) were found in your proposal. If your proposal doesn't correspond to a web feature, that is fine.
Otherwise, please update your initial comment to include web-features: <feature-id>.
To find feature IDs, use the web-features explorer.

[captainbrosset]

There's actually a web-features entry that matches this proposal: https://web-platform-dx.github.io/web-features-explorer/features/bfcache-blocking-reasons/
@yoavweiss if you edit your initial comment to mention this URL in it, the above comment will auto-update with additional information.

[yoavweiss]

@yoavweiss if you edit your initial comment to mention this URL in it, the above comment will auto-update with additional information.

Updated, thanks!!