We would like to extend Early Hints preload/preconnect Origin Trial to M98 (originally planned to end in M96).
Contact emailsba...@chromium.org, yhir...@chromium.org, denom...@chromium.org Explainer https://github.com/bashi/early-hints-explainer/blob/main/explainer.md Specificationhttps://tools.ietf.org/html/rfc8297 Design docs https://docs.google.com/document/d/1gCh_CnfrJq_VL7aGoq6skc7sn4yn5pKsM0gkHe5B9go/edit?usp=sharing Summary Support 103 Early Hints informational responses for navigation. When a 103 response includes <link rel=preload> or other link headers Chromium tries to preload (and/or preconnect, prefetch) specified resources even before the final response is received. This gives Web developers a way to optimize Core Web Vitals such as Largest Contentful Paint (LCP). Blink componentInternals>Preload <https://bugs.chromium.org/p/chromium/issues/list?q=component:Internals%3EPreload> TAG reviewhttps://github.com/w3ctag/design-reviews/issues/638 TAG review statusPending Risks Interoperability and Compatibility Several servers/proxies may not understand a 103 response. They may treat the 103 response as a part of the final response when the response is sent over HTTP/1.1. The problem is less likely to happen over HTTP/2 thanks to their frame format. Chromium only handles 103 responses over HTTP/2 and HTTP/3. Gecko: Worth prototyping ( https://github.com/mozilla/standards-positions/issues/134) WebKit: No signal ( https://lists.webkit.org/pipermail/webkit-dev/2021-May/031861.html) Web developers: Positive ( https://www.fastly.com/blog/faster-websites-early-priority-hints) Web developers: Positive ( https://www.fastly.com/blog/faster-websites-early-priority-hints) Positive interest and intent of support by popular CDNs. We've been collaborating with Fastly to do the preliminary measurement. Goals for experimentation Allows web developers to opt-in Early Hints preloads. We use custom page load metrics (FCP, LCP FID) to measure performance impact. Reason this experiment is being extended We added preconnect support in M95 based on Web developer's feedback and we are now evaluating the impact of preload and preconnect. We realized that we need more time to evaluate the impact of this feature. We have partners lined up for the feature and we expect to get more data in coming months. Ongoing technical constraints None Debuggability If a resource is preloaded by Early Hints, the corresponding PerformanceResourceTiming object reports initiatorType is "early-hints". For more details, see https://chromium.googlesource.com/chromium/src/+/refs/heads/main/docs/early-hints.md#checking-early-hints-preload-is-working 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 nameEarlyHintsPreloadForNavigation Requires code in //chrome?False Tracking bughttps://crbug.com/671310 Launch bughttps://crbug.com/1197989 Estimated milestones OriginTrial desktop last 95 → *98* OriginTrial desktop first 94 OriginTrial android last 95 → *98* OriginTrial android first 94 Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5207422375297024 Links to previous Intent discussionsIntent to Experiment: https://groups.google.com/u/1/a/chromium.org/g/blink-dev/c/xb_NHDS3twY 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/CAPLXX-8G77uvOt6%3DomTRhQBS%2BcmxB6UaAbeeHiKRRumMPnd8bg%40mail.gmail.com.
