Well done, thanks for the contribution! On Tue, Jan 6, 2026 at 10:09 AM Ane Diaz De Tuesta <[email protected]> wrote:
> Hi all, > > Thank you to *chrishtr@*, *miketaylr@*, and *yoavweiss@* for the LGTMs! > (and *barryp@* for your guidance!) > > I'm happy to report that this feature has now shipped: > ✅ All review gates completed (Privacy, Security, Enterprise, Testing, > Debuggability) > ✅ Flag CL merged: > https://chromium-review.googlesource.com/c/chromium/src/+/7261417 > ✅ CLS changelog updated > ✅ Shipped in Chrome 145 > > The Layout Instability API now reports attribution rectangles in CSS > pixels by default, improving consistency with other Web Platform APIs. > > Should I update the ChromeStatus page to reflect that all changes have > been addressed? If yes, what fields should I update? > > Thanks again to everyone who provided feedback and guidance throughout > this process! > > Le lundi 5 janvier 2026 à 16:57:29 UTC+1, Ane Diaz De Tuesta a écrit : > >> This is amazing — thank you both! >> Since all the gates are approved, the final step to ship the feature is >> to merge the CL that promotes ReportLayoutShiftRectsInCssPixels to stable: >> https://chromium-review.googlesource.com/c/chromium/src/+/7261417 >> >> Mike, I added you as the code owner, since you’ve been incredibly helpful >> throughout this process. >> >> >> I can’t believe I’ll see this live soon 🤩 — my Christmas gift *after* >> Christmas 🙂 >> >> Thank you! >> Le lundi 5 janvier 2026 à 16:47:17 UTC+1, [email protected] a écrit : >> >>> Thanks Mike! I was just chasing the Chrome Tooling team on this to see >>> if anyone else could approve in his absence. They're aware of the change >>> and have been liaising with Ane on it. So good to approve. >>> >>> On Mon, 5 Jan 2026 at 15:41, Mike Taylor <[email protected]> wrote: >>> >>>> Hi Ane, >>>> >>>> The debuggability reviewer is OOO for the next week or so, but based on >>>> your answers I've gone ahead and approved the bit. >>>> >>>> thanks, >>>> Mike >>>> On 12/30/25 4:34 a.m., Ane Diaz De Tuesta wrote: >>>> >>>> Hi all, >>>> >>>> I'm following up on the Debuggability gate, which is currently showing >>>> as overdue by a day on ChromeStatus. I'd like to move forward with >>>> completing the Intent to Ship process. >>>> >>>> For context, this change modifies Layout Instability API attribution >>>> rectangles from device pixels to CSS pixels, a units change that aligns >>>> with other Web Platform APIs (getBoundingClientRect, IntersectionObserver, >>>> etc.). >>>> >>>> From a debuggability perspective: >>>> >>>> - The API continues to work identically, just reporting CSS pixels >>>> instead of device pixels >>>> - DevTools Layout Instability tracking remains unchanged >>>> - Developers can inspect the values the same way through the >>>> PerformanceObserver API >>>> >>>> If there are specific debuggability concerns or additional information >>>> needed, I'm happy to provide it. Otherwise, any guidance on how to move >>>> this gate forward would be greatly appreciated. >>>> >>>> Thanks! >>>> Ane :-) >>>> Le mercredi 17 décembre 2025 à 16:04:31 UTC+1, Chris Harrelson a écrit : >>>> >>>>> LGTM3 >>>>> >>>>> On Tue, Dec 16, 2025 at 6:38 AM Mike Taylor <[email protected]> >>>>> wrote: >>>>> >>>>>> This intent is visible in the API Owner review queue, so no need to >>>>>> ping (unless the thread goes silent for a ~week). >>>>>> On 12/16/25 8:06 a.m., Ane Diaz De Tuesta wrote: >>>>>> >>>>>> As discussed with Barry Pollard offline, in all web docs we assume >>>>>> that pixels = CSS pixels! >>>>>> When it's physical pixels that should be the exception that's >>>>>> documented. >>>>>> >>>>>> So after a second reflection, we finally got back to the conclusion >>>>>> that MDN doesn't need to be updated. >>>>>> >>>>>> Now, I am looking for my last API Owner approval, can I ping someone >>>>>> or approvers will show naturally? >>>>>> >>>>>> >>>>>> Thanks! >>>>>> Best, >>>>>> Ane >>>>>> >>>>>> Le mardi 16 décembre 2025 à 01:54:18 UTC+1, [email protected] a >>>>>> écrit : >>>>>> >>>>>>> LGTM2 (and thanks Barry for doing outreach to RUM providers). >>>>>>> On 12/15/25 4:53 a.m., Yoav Weiss (@Shopify) wrote: >>>>>>> >>>>>>> LGTM1 >>>>>>> >>>>>>> The main risk here is for tools that get their input from this data >>>>>>> and visualize it to users (where the data can be in either synthetic or >>>>>>> RUM). We mainly care about RUM data here, but even there, the direct >>>>>>> compat >>>>>>> risk for actual users is minimal. In other words, this change will not >>>>>>> create visible breakage for users, but may create one for developers >>>>>>> that >>>>>>> use tools that rely on this data. >>>>>>> >>>>>>> On Mon, Dec 15, 2025 at 10:20 AM 'Barry Pollard' via blink-dev < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>>> Not that I've discussed this previously with Ane and this may >>>>>>>> require changes to those tools using these pixels to create >>>>>>>> screenshots or >>>>>>>> animations of CLS. I've reached out directly to the primary tools I'm >>>>>>>> aware >>>>>>>> off in this space (Chrome DevTools, DebugBear, WebPageTest) as well as >>>>>>>> more >>>>>>>> general outreach on the likes of the Web Performance slack. Will >>>>>>>> continue >>>>>>>> that further now the I2S is published. >>>>>>> >>>>>>> >>>>>>> Thanks for the outreach! >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> It's a small change to accommodate this change, is not critical >>>>>>>> (the worst case is the wrong area of the screenshot/animation will be >>>>>>>> highlighted until the change is made) and brings the Layout >>>>>>>> Instability API >>>>>>>> inline with other Web Platform APIs and most would expect of this. So >>>>>>>> I'm >>>>>>>> supportive of this change, despite this risk. >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Barry >>>>>>>> >>>>>>>> On Friday, December 12, 2025 at 6:57:20 PM UTC [email protected] >>>>>>>> wrote: >>>>>>>> >>>>>>>>> # Contact emails >>>>>>>>> [email protected] >>>>>>>>> # Explainer >>>>>>>>> None (This is a small compatibility fix - the spec PR serves as >>>>>>>>> the explainer). The PR is a spec change, not an explainer. You can say >>>>>>>>> "None" or link to a separate explainer if you have one. >>>>>>>>> # Specification >>>>>>>>> https://wicg.github.io/layout-instability/ >>>>>>>>> # Summary >>>>>>>>> Change Layout Instability API attribution rectangles (`prevRect` >>>>>>>>> and `currentRect`) from device pixels to CSS pixels. This aligns >>>>>>>>> the API with other Web Platform measurement APIs >>>>>>>>> (getBoundingClientRect, >>>>>>>>> IntersectionObserver, ResizeObserver) that use CSS pixels as the >>>>>>>>> standard >>>>>>>>> coordinate system. >>>>>>>>> # Blink component >>>>>>>>> Blink>PerformanceAPIs >>>>>>>>> # Motivation >>>>>>>>> The current implementation uses device pixels, which: >>>>>>>>> - Creates inconsistencies across devices with different pixel >>>>>>>>> ratios >>>>>>>>> - Makes it difficult for developers to correlate layout shift >>>>>>>>> data with other measurements >>>>>>>>> - Deviates from the standard coordinate system used throughout >>>>>>>>> the web platform >>>>>>>>> CSS pixels provide a consistent, device-independent unit that >>>>>>>>> aligns with developer expectations and simplifies working with >>>>>>>>> layout stability metrics alongside other DOM measurements. >>>>>>>>> # TAG review Not applicable - This is a small compatibility fix >>>>>>>>> to an existing API, not a new feature. The change aligns Layout >>>>>>>>> Instability >>>>>>>>> API attribution rectangles with the standard CSS pixel coordinate >>>>>>>>> system >>>>>>>>> used by other Web Platform APIs. This does not introduce new API >>>>>>>>> surface or >>>>>>>>> capabilities. # TAG review status Not applicable # Chromium bug >>>>>>>>> https://issues.chromium.org/issues/399058544 >>>>>>>>> # Risks >>>>>>>>> ## Interoperability and Compatibility >>>>>>>>> **Interoperability risk:** Low. This is a measurement/telemetry >>>>>>>>> change that doesn't affect site functionality. The API is used >>>>>>>>> primarily by monitoring/analytics tools. >>>>>>>>> **Gecko:** Closed without a position ( >>>>>>>>> https://github.com/mozilla/standards-positions/issues/1318) - >>>>>>>>> Mozilla supports CSS pixels for web APIs, though they don't implement >>>>>>>>> the >>>>>>>>> Layout Instability API. >>>>>>>>> **WebKit:** No signal ( >>>>>>>>> https://github.com/WebKit/standards-positions/issues/588) >>>>>>>>> **Web developers:** Positive feedback from WebPerf Slack >>>>>>>>> community. The change simplifies working with layout stability >>>>>>>>> metrics. >>>>>>>>> **Compatibility risk:** Low. Primary consumers are telemetry >>>>>>>>> systems (RUM providers, analytics tools) that can adapt their >>>>>>>>> processing. The change provides more consistent, useful data. >>>>>>>>> Sites using the API directly will see coordinate values change but can >>>>>>>>> easily adapt by removing device pixel ratio conversions. >>>>>>>>> **Rollback plan:** Feature can be disabled via flag if unexpected >>>>>>>>> issues arise. >>>>>>>>> # Ergonomics >>>>>>>>> This change improves ergonomics by aligning with the CSS pixel >>>>>>>>> coordinate system developers already use in other APIs >>>>>>>>> (getBoundingClientRect, IntersectionObserver, ResizeObserver), >>>>>>>>> reducing >>>>>>>>> confusion and simplifying debugging. >>>>>>>>> # Activation >>>>>>>>> No user activation required - this is a measurement/telemetry API. # >>>>>>>>> Security >>>>>>>>> No security concerns - this changes the unit of measurement for >>>>>>>>> existing data, does not expose new information. # WebView >>>>>>>>> application risks >>>>>>>>> None. This is a measurement/telemetry change that works >>>>>>>>> consistently across all platforms including WebView. >>>>>>>>> # Debuggability >>>>>>>>> No changes to debuggability. The API continues to work the same >>>>>>>>> way, just with CSS pixel coordinates instead of device pixels. >>>>>>>>> # 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? >>>>>>>>> Yes. Web Platform Tests have been updated to verify CSS pixel >>>>>>>>> behavior for attribution rectangles. >>>>>>>>> WPT link: >>>>>>>>> https://wpt.fyi/results/layout-instability/attribution-rectangles-css-pixels.html >>>>>>>>> # Flag name on chrome://flags >>>>>>>>> None (controlled by base::Feature) >>>>>>>>> # Finch feature name >>>>>>>>> None - shipping enabled by default for all users. This is a >>>>>>>>> low-risk compatibility fix to a measurement API with good test >>>>>>>>> coverage. >>>>>>>>> # Non-Finch justification >>>>>>>>> This is a compatibility fix to align the Layout Instability API >>>>>>>>> with standard Web Platform coordinate systems. The change affects >>>>>>>>> measurement data rather than user-facing functionality, and has low >>>>>>>>> risk of >>>>>>>>> breakage. Primary consumers are RUM/analytics tools that can adapt to >>>>>>>>> the >>>>>>>>> change. >>>>>>>>> # Requires code in //chrome? >>>>>>>>> No. >>>>>>>>> # Estimated milestones >>>>>>>>> Shipping on desktop: 145 >>>>>>>>> Shipping on Android: 145 >>>>>>>>> # Spec changes >>>>>>>>> Spec PR merged: >>>>>>>>> https://github.com/WICG/layout-instability/pull/125 (Clarifies >>>>>>>>> that attribution rectangles use CSS pixels, consistent with other Web >>>>>>>>> Platform APIs) >>>>>>>>> # Link to entry on the Chrome Platform Status >>>>>>>>> https://chromestatus.com/feature/5155103518228480 >>>>>>>>> # Links to previous Intent discussions >>>>>>>>> Intent to Prototype: >>>>>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/EMlUrEwx_uE/m/pxBix6wWDAAJ?utm_medium=email&utm_source=footer >>>>>>>>> --- >>>>>>>>> **This intent message was generated by Chrome Platform Status.** >>>>>>>>> Security and Privacy reviews have been approved via ChromeStatus >>>>>>>>> gates. >>>>>>>>> Implementation CL: >>>>>>>>> https://chromium-review.googlesource.com/c/chromium/src/+/6624567 >>>>>>>>> --- >>>>>>>>> >>>>>>>> -- >>>>>>>> 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/1a72af4d-f574-488a-913e-a98135d3afban%40chromium.org >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/1a72af4d-f574-488a-913e-a98135d3afban%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 [email protected]. >>>>>>> >>>>>>> To view this discussion visit >>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohSKPSqnxw8PAizjj%3DT9yPLWMobxv3BOgJ7J-MEkD0_qB0w%40mail.gmail.com >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohSKPSqnxw8PAizjj%3DT9yPLWMobxv3BOgJ7J-MEkD0_qB0w%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/159d7198-045f-46a8-b1e9-a0f8a85c06fe%40chromium.org >>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/159d7198-045f-46a8-b1e9-a0f8a85c06fe%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 [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/44922610-8f72-4c25-99a2-51ace64ce428n%40chromium.org > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/44922610-8f72-4c25-99a2-51ace64ce428n%40chromium.org?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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