LGTM On Thu, Jul 24, 2025 at 12:48 PM 'Mike Jackson' via blink-dev < blink-dev@chromium.org> wrote:
> Contact emails > mjack...@microsoft.com, mmo...@google.com, mjack...@chromium.org > > Explainer > > https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/PerformanceNavigationTiming%20for%20User%20Agent%20Launch/explainer.md > > Specification > > https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/PerformanceNavigationTiming%20for%20User%20Agent%20Launch/explainer.md > > Design docs > > https://docs.google.com/document/d/1D6DqptsCEd3wPRsZ0q1iwVBAXXmhxZuLV-KKFI0ptCg/edit#heading=h.7nki9mck5t64 > > Summary > > Web applications may suffer from bimodal distribution in page load > performance, due to factors outside of the web application’s control. For > example: * When a user agent first launches (a "cold start" scenario), it > must perform many expensive initialization tasks that compete for resources > on the system. * Browser extensions can affect the performance of a > website. For instance, some extensions run additional code on every page > you visit, which can increase CPU usage and result in slower response > times. * When a machine is busy performing intensive tasks, it can lead to > slower loading of web pages. In these scenarios, content the web app > attempts to load will be in competition with other work happening on the > system. This makes it difficult to detect if performance issues exist > within web applications themselves, or because of external factors. Teams > we have worked with have been surprised at the difference between > real-world dashboard metrics and what they observe in page profiling tools. > Without more information, it is challenging for developers to understand if > (and when) their applications may be misbehaving or are simply being loaded > in a contended period. A new ‘confidence’ field on the > PerformanceNavigationTiming object will enable developers to discern if the > navigation timings are representative for their web application. > > > Blink component > Blink>PerformanceAPIs>NavigationTiming > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EPerformanceAPIs%3ENavigationTiming%22> > > TAG review > https://github.com/w3ctag/design-reviews/issues/878 > > TAG review status > Issues addressed > > Origin Trial Name > PerformanceNavigationTiming confidence > > Chromium Trial Name > PerformanceNavigationTimingConfidence > > Origin Trial documentation link > https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/PerformanceNavigationTiming%20for%20User%20Agent%20Launch/explainer.md > > WebFeature UseCounter name > kPerformanceNavigationTimingConfidence > > Risks > > > Interoperability and Compatibility > > None. > > > *Gecko*: No signal ( > https://github.com/mozilla/standards-positions/issues/1191) > > *WebKit*: No signal ( > https://github.com/WebKit/standards-positions/issues/469) > > *Web developers*: No signals > > *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 > > > > Reason this experiment is being extended > > Our partner adopted the feature, but a site bug caused data to be > collected too early during the page lifecycle. They've resolved the issue > and requested three additional releases to gather data and ensure > integration into their performance dashboard. > > > Ongoing technical constraints > > > > Debuggability > > > > Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)? > Yes > > Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> > ? > Yes > > > third_party/blink/web_tests/http/tests/misc/performance-navigation-timing-entry-confidence.tentative.html > > > Flag name on about://flags > > Finch feature name > PerformanceNavigationTimingConfidence > > Requires code in //chrome? > True > > Tracking bug > https://bugs.chromium.org/p/chromium/issues/detail?id=1413848 > > Estimated milestones > Origin trial desktop first > 136 > Origin trial desktop last > 139 > Origin trial extension 1 end milestone > 142 > DevTrial on desktop > 135 > Origin trial Android first > 136 > Origin trial Android last > 139 > DevTrial on Android > 135 > > Link to entry on the Chrome Platform Status > https://chromestatus.com/feature/5186950448283648?gate=5077717401468928 > > Links to previous Intent discussions > Intent to Prototype: > https://groups.google.com/a/chromium.org/g/blink-dev/c/o0F7nBKsgg0/m/bJSp3ekfAAAJ > Intent to Experiment: > https://groups.google.com/a/chromium.org/g/blink-dev/c/FYsfp0OsMko/m/WbhUrqSqAQAJ > > > This intent message was generated by Chrome Platform Status > <https://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 visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6091e78f-7c77-4ed3-9559-eb660a14dfb7n%40chromium.org > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6091e78f-7c77-4ed3-9559-eb660a14dfb7n%40chromium.org?utm_medium=email&utm_source=footer> > . > -- 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 visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw8RdBRRVB7Kim_G6KDSKLO_Jjrv7azseTNmF7J%3DEvn34w%40mail.gmail.com.
