Hi API Owners, I have to make a correction here since we misread the usage in the dashboard. We are actually still seeing ~1% usage. Given this new information, the revised plan for which we seek approval is: - 10% Stable: Hold for 2 weeks (through Oct 12) - 100% Stable: Roll out starting Oct 26
Thanks for your consideration, --Benjamin "Russ" Hamilton On Wed, Sep 23, 2026 at 9:10 AM Russ Hamilton <[email protected]> wrote: > Hi API Owners, > > We have seen no regressions on 1% of stable (M152+) so we request > permission to proceed with full removal of the API. This corresponds to > step 4 of the plan Paul proposed in June. Given the low usage (<0.005%) we > plan to move directly to removing these APIs on 100% of Chrome M152+. > > Thanks for your consideration, > --Benjamin "Russ" Hamilton > > On Mon, Sep 7, 2026 at 4:35 AM Anton Bershanskyi <[email protected]> > wrote: > >> Hi Paul, >> >> the email form Jun 12 states that Protected Audience API implementation >> would be removed in M152. When I test on Chrome 152 stable, >> both navigator.joinAdInterestGroup and navigator.runAdAuction exist. Chrome >> Status entry <https://chromestatus.com/feature/6552486106234880> states >> that removal is planned for M153. Did the removal milestone get postponed >> by a milestone from 152 to 153? >> >> Sincerely, >> Anton. >> >> On Saturday, July 18, 2026 at 11:38:05 PM UTC+3 Garrett Johnson wrote: >> >>> Paul, >>> Thanks for taking the time to respond and explain. This is a useful for >>> me to refer to when explaining this to the reader. >>> Warm regards, >>> >>> Garrett >>> >>> On Thursday, 16 July 2026 at 13:48:55 UTC-4 Paul Jensen wrote: >>> >>>> Garrett, >>>> >>>> >>>> When we marked the Protected Audience API as deprecated, in >>>> crrev.com/1545185, this included more of the API surface into the >>>> “Fledge” Blink use counter. You can see we added “DeprecateAs=Fledge” to a >>>> lot of the APIs in navigator_auction.idl in that change. It wasn’t >>>> actually an increase in API usage, it was just a change in measurement. >>>> You can see there were no corresponding spikes in particular API usage: >>>> https://chromestatus.com/metrics/feature/timeline/popularity/3855 >>>> https://chromestatus.com/metrics/feature/timeline/popularity/3857 >>>> >>>> On Tuesday, July 14, 2026 at 10:50:58 AM UTC-4 Garrett Johnson wrote: >>>> >>>>> I'm a researcher in this space who has ongoing research >>>>> <https://ssrn.com/abstract=4983927> measuring the adoption and use of >>>>> Privacy Sandbox tools. >>>>> >>>>> I'm hoping that someone in this chain could resolve a mystery for me >>>>> about the Fledge usage metrics in the Chrome Platform Status data here >>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4188>. >>>>> Basically, this approaches 0% of page loads in Q4 2025 as you would expect >>>>> given its retirement. However, usage spikes to its highest ever usage in >>>>> Q1 >>>>> 2026 (peaking at 7.7%). This is unexpected: as mentioned above, auctions & >>>>> interest group activity has gone to almost 0 in the Chrome Platform Status >>>>> data (and my own). My guess is that some deprecation flag is being counted >>>>> here, but I really don't know. Other researchers >>>>> <https://arxiv.org/abs/2606.26390> found a similar spike in the HTTP >>>>> Archive data. >>>>> >>>>> I'd really appreciate your input here in setting the record straight >>>>> on whether PA API's post-retirement was in fact a mirage. Big bonus points >>>>> if you can explain why this happened. >>>>> >>>>> Sincerely, >>>>> >>>>> Garrett Johnson >>>>> Associate Professor >>>>> Questrom School of Business >>>>> Boston University >>>>> https://garjoh.com >>>>> >>>>> On Wednesday, 1 July 2026 at 14:25:39 UTC-4 Daniel Bratell wrote: >>>>> >>>>>> LGTM3 for steps 2 and 3. >>>>>> >>>>>> /Daniel >>>>>> On 2026-06-25 19:05, Chris Harrelson wrote: >>>>>> >>>>> LGTM2 >>>>>> >>>>>> On Thu, Jun 25, 2026 at 9:56 AM Yoav Weiss (@Shopify) < >>>>>> [email protected]> wrote: >>>>>> >>>>>> LGTM1 >>>>>>> >>>>>>> On Fri, Jun 12, 2026 at 2:32 AM Paul Jensen <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>> Hi API Owners, Protected Audience API was deprecated in Chrome-144 >>>>>>>> with a plan to remove it in Chrome-150. Currently the usage is 1.1% >>>>>>>> of page loads. >>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4188>We >>>>>>>> are proposing the following as next steps for removal and associated >>>>>>>> timelines: 1. M150: Remove all Ads API-related entries from Chrome >>>>>>>> settings and UI surfaces (e.g., chrome://settings/adPrivacy) via >>>>>>>> field trial. After this point, all API invocations for field-trial >>>>>>>> enabled >>>>>>>> browsers will always reject. Since the API can already be disabled for >>>>>>>> one >>>>>>>> of many reasons, scripts must already handle such rejections (or >>>>>>>> they’re >>>>>>>> already significantly broken). 2. M152: Permanently remove the >>>>>>>> underlying implementation code for the API, and replace it with a >>>>>>>> lightweight stub API. The stub will remain removable via field trial. >>>>>>>> >>>>>>>> 3. M152 Canary/Beta: Begin a controlled rollout of the stub API >>>>>>>> removal via a field trial. 4. M152 Stable: Assuming there are no >>>>>>>> regressions or breakage after reaching 1% stable, we will request >>>>>>>> additional approval for full removal at this stage. >>>>>>>> >>>>>>>> At this time, we are seeking LGTMs for steps #2 and #3. >>>>>>>> >>>>>>>> Thanks, >>>>>>>> >>>>>>>> Paul >>>>>>>> >>>>>>>> On Wed, Nov 12, 2025 at 11:30 AM Vladimir Levin < >>>>>>>> [email protected]> wrote: >>>>>>>> >>>>>>> LGTM2 >>>>>>>>> >>>>>>>>> On Wednesday, November 12, 2025 at 11:30:32 AM UTC-5 Chris >>>>>>>>> Harrelson wrote: >>>>>>>>> >>>>>>>> LGTM1 >>>>>>>>>> >>>>>>>>>> On Fri, Nov 7, 2025 at 11:04 AM Paul Jensen < >>>>>>>>>> [email protected]> wrote: >>>>>>>>>> >>>>>>>>> Intent to Deprecate and Remove: Protected Audience >>>>>>>>>>> Contact emails >>>>>>>>>>> >>>>>>>>>> [email protected] >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Explainer >>>>>>>>>>> >>>>>>>>>>> https://github.com/WICG/turtledove/blob/main/FLEDGE.md >>>>>>>>>>> >>>>>>>>>>> Specification >>>>>>>>>>> >>>>>>>>>>> https://wicg.github.io/turtledove/ >>>>>>>>>>> >>>>>>>>>>> Summary The Protected Audience API provides a method of >>>>>>>>>>> interest-group advertising without third-party cookies or user >>>>>>>>>>> tracking >>>>>>>>>>> across sites. >>>>>>>>>>> >>>>>>>>>>> Following Chrome's announcement >>>>>>>>>>> <https://privacysandbox.com/news/privacy-sandbox-next-steps/> >>>>>>>>>>> that the current approach to third-party cookies will be >>>>>>>>>>> maintained, we are >>>>>>>>>>> now planning to deprecate and remove >>>>>>>>>>> <https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/> >>>>>>>>>>> the Protected Audience API (along with certain other Privacy >>>>>>>>>>> Sandbox APIs, >>>>>>>>>>> as outlined on the Privacy Sandbox feature status page >>>>>>>>>>> <https://privacysandbox.google.com/overview/status>). >>>>>>>>>>> >>>>>>>>>>> Blink component >>>>>>>>>>> >>>>>>>>>>> Blink>InterestGroups >>>>>>>>>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EInterestGroups%22> >>>>>>>>>>> >>>>>>>>>>> Web Feature ID >>>>>>>>>>> >>>>>>>>>>> None >>>>>>>>>>> >>>>>>>>>>> Motivation >>>>>>>>>>> >>>>>>>>>>> Chrome has announced that the current approach to third-party >>>>>>>>>>> cookies will be maintained. Since that announcement there has >>>>>>>>>>> been virtually no interest in the Protected Audience API. Use >>>>>>>>>>> of the joinAdInterestGroup() API >>>>>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/3855> >>>>>>>>>>> has decreased by almost 100x and use of the runAdAuction() API >>>>>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/3857> >>>>>>>>>>> has decreased by more than 10x. Of the auctions occurring today, >>>>>>>>>>> virtually >>>>>>>>>>> none of them have winners (determined by looking at the “Success” >>>>>>>>>>> bucket >>>>>>>>>>> count of the Ads.InterestGroup.Auction.Result UMA), implying that >>>>>>>>>>> they are >>>>>>>>>>> not providing useful benefit to the pages initiating them. >>>>>>>>>>> >>>>>>>>>>> Initial public proposal >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/ >>>>>>>>>>> . >>>>>>>>>>> >>>>>>>>>>> Developer-facing impact >>>>>>>>>>> >>>>>>>>>>> Given that virtually none of the Protected Audience auctions >>>>>>>>>>> occurring today have winners, we estimate the lost utility from this >>>>>>>>>>> removal to be negligible. >>>>>>>>>>> >>>>>>>>>>> User-facing risks >>>>>>>>>>> >>>>>>>>>>> The user-facing risks are small. While removing the JavaScript >>>>>>>>>>> API could cause pages to break, the impact should be limited to >>>>>>>>>>> sites that >>>>>>>>>>> don't employ standard defensive coding or feature detection, which >>>>>>>>>>> should >>>>>>>>>>> be rare since not all browsers implement the API. >>>>>>>>>>> >>>>>>>>>>> If usage warrants, we will take steps to avoid any risk of page >>>>>>>>>>> breakage, e.g. by temporarily retaining a stub implementation of >>>>>>>>>>> Navigator >>>>>>>>>>> APIs joinAdInterestGroup(), runAdAuction(), leaveAdInterestGroup(), >>>>>>>>>>> clearOriginJoinedAdInterestGroups(), >>>>>>>>>>> getInterestGroupAdAuctionData(), >>>>>>>>>>> canLoadAdAuctionFencedFrame(), createAuctionNonce(), >>>>>>>>>>> updateAdInterestGroups(), protectedAudience.queryFeatureSupport(), >>>>>>>>>>> deprecatedReplaceInURN(), deprecatedURNtoURL(), and >>>>>>>>>>> adAuctionComponents() >>>>>>>>>>> that mimic current behavior when a user has disabled Protected >>>>>>>>>>> Audience. >>>>>>>>>>> >>>>>>>>>>> Estimated milestones >>>>>>>>>>> >>>>>>>>>>> Planning to deprecate in M144 and remove in M150. >>>>>>>>>>> >>>>>>>>>>> Currently 0.22% >>>>>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4188> >>>>>>>>>>> of page loads use the Protected Audience API. These are driven by a >>>>>>>>>>> small >>>>>>>>>>> number of third-party ad tech scripts present on a large number of >>>>>>>>>>> sites. >>>>>>>>>>> We will continue to monitor usage as well as provide comprehensive >>>>>>>>>>> updates >>>>>>>>>>> on privacysandbox.google.com with the status of the API and >>>>>>>>>>> deprecation plans >>>>>>>>>>> <https://privacysandbox.google.com/overview/status>. >>>>>>>>>>> >>>>>>>>>>> We will also proactively work toward reducing usage to low >>>>>>>>>>> levels once this intent is approved, including disallowing any new >>>>>>>>>>> enrollment sign-ups, and contacting enrolled sites to inform them >>>>>>>>>>> about the >>>>>>>>>>> deprecation timelines. >>>>>>>>>>> >>>>>>>>>>> Protected Audience features that were never launched beyond 20% >>>>>>>>>>> Stable (TextEncoder support >>>>>>>>>>> <https://github.com/WICG/turtledove/issues/961#issuecomment-2793763963>, >>>>>>>>>>> Creative scanning via BYOS/V1 trusted scoring signals >>>>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/EXfp34Qb1oc/m/oaiY6MENBwAJ>, >>>>>>>>>>> Selectable Reporting IDs >>>>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/1cWqBPHngd0/m/gSYeR_dPAAAJ>) >>>>>>>>>>> will be ramped down by the end of 2025. >>>>>>>>>>> >>>>>>>>>>> Protected Audience services, Bidding and Auction services >>>>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/CyXJz3xOEcc/m/1snkv2KhAwAJ> >>>>>>>>>>> and Trusted Key Value service >>>>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/fH8u7ZTNZg8/m/oo0WVw7SAQAJ>, >>>>>>>>>>> will not onboard new clients once deprecation is approved. We will >>>>>>>>>>> work >>>>>>>>>>> with onboarded clients and plan to turn down the services by the >>>>>>>>>>> end of >>>>>>>>>>> year as usage is negligible today. This will have no user-facing or >>>>>>>>>>> web-compat impact. >>>>>>>>>>> >>>>>>>>>>> Link to entry on the Chrome Platform Status >>>>>>>>>>> >>>>>>>>>>> https://chromestatus.com/feature/6552486106234880 >>>>>>>>>>> >>>>>>>>>> -- >>>>>>>>>>> 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/CABQTWrnevtY14OMos%2BuDgzXtFwQJ5vzY3hEMmyRFQBKDHBz-9A%40mail.gmail.com >>>>>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrnevtY14OMos%2BuDgzXtFwQJ5vzY3hEMmyRFQBKDHBz-9A%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/CABQTWrmRRxZO%3D%2BCmt-hfkBBjeR8j4umTer8krMvmAyiVP_1HXw%40mail.gmail.com >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrmRRxZO%3D%2BCmt-hfkBBjeR8j4umTer8krMvmAyiVP_1HXw%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/CAOmohS%2BRQAUtSUZw%3D4TsVgNOxcuR5aeQhym2CZO-_WmzUnndLQ%40mail.gmail.com >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohS%2BRQAUtSUZw%3D4TsVgNOxcuR5aeQhym2CZO-_WmzUnndLQ%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/CAOMQ%2Bw94fqnFNWSUWQSm7crPrzuLbO6Cz5p9Rg0BLEJsU%3DHPPg%40mail.gmail.com >>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw94fqnFNWSUWQSm7crPrzuLbO6Cz5p9Rg0BLEJsU%3DHPPg%40mail.gmail.com?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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