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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.
