LGTM2 On Wednesday, October 29, 2025 at 4:10:14 PM UTC+1 Chris Harrelson wrote:
> LGTM1 > > On Wed, Oct 29, 2025 at 7:44 AM 'Michal Mocny' via blink-dev < > [email protected]> wrote: > >> (I have updated the target milestone to 144) >> >> On Wed, Oct 22, 2025 at 5:41 PM Chromestatus < >> [email protected]> wrote: >> >>> *Contact emails* >>> [email protected] >>> >>> *Specification* >>> https://www.w3.org/TR/event-timing/#dom-performance-interactioncount >>> >>> *Design docs* >>> *No information provided* >>> https://www.w3.org/TR/event-timing/#dom-performance-interactioncount >>> https://www.w3.org/TR/event-timing/#sec-increasing-interaction-count >>> >>> *Summary* >>> The Event Timing API is part of the Performance Timeline and is used to >>> measure the performance of user interactions. Certain Events will have an >>> interactionId value assigned to them, and this is useful for grouping >>> related interactions based on common physical user inputs or gestures. This >>> feature adds a very trivial performance.interactionCount, which is just the >>> total number of interactions that have occured on the page. In particular, >>> this feature is useful for computing the Interaction to Next Paint (INP) >>> metric value, which requires knowing the total number of interactions in >>> order to compute a high percentile score (p98 for pages with greater than >>> 50 total interactions). This feature has been specced for a long while, was >>> prototypes in Chromium a long time ago but never shipped, is part of >>> Interop 2025, and is already available in other browsers. (Note: there is >>> already a more powerful performance.eventCounts map for specific events, >>> but it is not possible to accurately map event cunts to interaction >>> counts.) >>> >>> *Blink component* >>> Blink>PerformanceAPIs >>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EPerformanceAPIs%22> >>> >>> *Web Feature ID* >>> event-timing <https://webstatus.dev/features/event-timing> >>> >>> *Motivation* >>> Used to count the number of important real user interactions with a >>> page. This is distinct from counting the number of events that Event Timing >>> measures (because a single physical user gesture may fire many, variable >>> number, of specific events, depending on the type of input and event target >>> and page design) but you can already count interactions (inconveniently) by >>> just counting the number of unique interactionId values in Event Timing >>> API. Used for calculating Interaction to Next Paint (INP) metric. >>> >>> *Initial public proposal* >>> *No information provided* >>> >>> *TAG review* >>> *No information provided* >>> >>> *TAG review status* >>> Not applicable >>> >>> *Risks* >>> >>> >>> *Interoperability and Compatibility* >>> Other browser venders have already shipped this feature as part of the >>> Interop 2025 effort for CWV INP. The main interop risk is that there are >>> existing polyfills for interactionCount in Chromium for INP calculation. >>> However, popular polyfills (such as web-vitals.js) have long been tested to >>> feature detect, given the long experimental web platform implementation in >>> chromium. >>> >>> *Gecko*: Shipped/Shipping ( >>> https://groups.google.com/a/mozilla.org/g/dev-platform/c/xvv6sxJZc4U/m/JzSSCoxPAgAJ?e=48417069 >>> ) >>> >>> *WebKit*: In development (https://bugs.webkit.org/show_bug.cgi?id=297361 >>> ) >>> >>> *Web developers*: Strongly positive No specific link, but this feature >>> is related to the very popular INP metric definition (and obviates the need >>> for an imperfect polyfill for counting interactions). >>> >>> *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? >>> n/a >>> >>> >>> *Debuggability* >>> DevTools has existing support for Interactions (real time performance >>> monitor and tracing). Visualizing total interactionCount is not needed, but >>> can be easily found (via literally counting the list of interactions, or >>> just console logs). >>> >>> *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 >>> https://wpt.fyi/results/event-timing/ (several tests, look for >>> interaction-count-*) >>> >>> *Flag name on about://flags* >>> *No information provided* >>> >>> *Finch feature name* >>> EventTimingInteractionCount >>> >>> *Rollout plan* >>> Will ship enabled for all users >>> >>> *Requires code in //chrome?* >>> False >>> >>> *Availability expectation* >>> Feature is available on Web Platform Baseline within 12 months of launch >>> in Chrome (as part of Interop 2025 for INP) >>> >>> *Adoption expectation* >>> Polyfill already widely adopted (for INP calculation), and feature >>> detection already used. >>> >>> *Estimated milestones* >>> Shipping on desktop 143 >>> DevTrial on desktop 111 >>> Shipping on Android 143 >>> DevTrial on Android 111 >>> Shipping on WebView 143 >>> >>> *Anticipated spec changes* >>> >>> Open questions about a feature may be a source of future web compat or >>> interop issues. Please list open issues (e.g. links to known github issues >>> in the project for the feature specification) whose resolution may >>> introduce web compat/interop risk (e.g., changing to naming or structure of >>> the API in a non-backward-compatible way). >>> Already specced in Event Timing API. >>> >>> *Link to entry on the Chrome Platform Status* >>> https://chromestatus.com/feature/5153386492198912?gate=5819984274128896 >>> >>> 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 [email protected]. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAEeF2TfFNGGAvfWM0cbTXG%2B5G4-_Uud5eGQi%3DZ5r2A1%2BwCskEg%40mail.gmail.com >> >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAEeF2TfFNGGAvfWM0cbTXG%2B5G4-_Uud5eGQi%3DZ5r2A1%2BwCskEg%40mail.gmail.com?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 [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/e1bd3a0d-2a6a-4413-a19c-b4d250ad0ea7n%40chromium.org.
