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Explainerhttps://github.com/WICG/priority-hints/blob/main/EXPLAINER.md Specificationhttps://wicg.github.io/priority-hints/ Summary Priority Hints provide developers a way to indicate a resource's relative importance to the browser, allowing more control over the order resources are loaded. Many factors influence a resource's priority in browsers. These include type, visibility, and preload status of a resource. Priority Hints introduces a developer-set "importance" attribute allowing developers to influence the computed priority of a resource. Supported importance values are auto, low, and high. Blink componentBlink>Loader <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3ELoader> Search tagspriority-hints <https://www.chromestatus.com/features#tags:priority-hints>, priority hints <https://www.chromestatus.com/features#tags:priority%20hints> TAG review TAG review statusPending Risks Interoperability and Compatibility Gecko: No signal WebKit: No signal Web developers: Strongly positive Goals for experimentation The goal is to re-start the origin trial experiment for Priority Hints with a focus on some specific use cases that have generated significant developer interest: * Boost the priority of the LCP image for a page by specifying importance="high" on the image element, causing LCP to happen sooner. * Increase the priority of async scripts using better semantics than the current hack that is commonly used (inserting a link preload for the async script) * Decreasing the priority of late-body scripts to allow for better sequencing with images. * Decreasing the priority of CSS to allow for sequencing with parser-blocking scripts. * Allow for varying priorities of javascript-initiated fetches. The bulk of the experiment will be focused on making sure the API surface meets developers needs and works as expected. The previous experiment was run 2 years ago before the recent focus on core web vitals and LCP in particular and did not generate as much developer interest as there is now. There were also prioritization issues with preload that are fixed in 95 that made it difficult to experiment with for the script case. There is pretty significant demand from developers for the knobs that Priority Hints provide, particularly for improving LCP. Ongoing technical constraints None Debuggability Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)?Yes Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md> ?No Flag name Requires code in //chrome?False Tracking bughttps://crbug.com/821464 Estimated milestones OriginTrial desktop last 101 OriginTrial desktop first 96 OriginTrial android last 101 OriginTrial android first 96 Link to entry on the Chrome Platform Status https://www.chromestatus.com/feature/5273474901737472 Links to previous Intent discussionsIntent to Experiment: https://groups.google.com/a/chromium.org/g/blink-dev/c/jpeSdM897Xw/m/CY6tothSDgAJ This intent message was generated by Chrome Platform Status <https://www.chromestatus.com/>. -- 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 blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAPq58w7f0siM7vz0-e2F7_8QfMEH_ZaG-8ga27_4vFp4493gbA%40mail.gmail.com.
