LGTM1 to deprecate. The plan to keep deprecation for 6 milestones also sounds good. Please come back after to this thread at a time when you think the removal can proceed. Since the amount of page loads is extremely high, we would like to reserve the right to pause the removal if this amount of page loads does not decrease substantially.
On Friday, November 7, 2025 at 1:12:36 PM UTC-5 Yao Xiao wrote: > Intent to Deprecate and Remove: Topics API > > Contact emails > > [email protected] > > Explainer > > https://github.com/patcg-individual-drafts/topics > > Specification > > https://patcg-individual-drafts.github.io/topics/ > > Summary > > The Topics API is a privacy-preserving web API to enable ad-targeting > based on a person’s general browsing interests, without exposing their > exact browsing history. > > Following Chrome's announcement that the current approach to third-party > cookies will be maintained, we are now planning to deprecate and remove the > Topics API (along with other Privacy Sandbox APIs). > > The following API surfaces will be affected: > > - > > The JavaScript function `document.browsingTopics()` will be removed. > - > > The `browsingtopics` attribute on <iframe> and <img> elements will be > ignored. > - > > The `browsingTopics` option in the fetch() API's RequestInit will be a > no-op. > - > > Consequently, the `Sec-Browsing-Topics` request header will no longer > be sent, and the `Observe-Browsing-Topics` response header will no longer > be honored. > - > > The "browsing-topics" and "interest-cohort" permissions policy > features will be removed. > > > Blink component > > Blink>TopicsAPI > <https://issues.chromium.org/u/1/issues?q=customfield1222907:%22Blink%3ETopicsAPI%22> > > Web Feature ID > > None > > Motivation > > Chrome has announced that the current approach to third-party cookies will > be maintained. Given this, we expect adoption to decrease over time > (currently at 13% > <https://chromestatus.com/metrics/feature/timeline/popularity/5102> of > page loads) as interest based advertising will remain possible in Chrome > using third-party cookies. Further, other browser engines have not signaled > interest in launching the API. See also the initial public proposal below. > > Initial public proposal > > > https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/ > . > > Possible breakage > > Sites that rely on Topics API for targeting will experience utility impact. > > If usage warrants, we will take steps to avoid any risk of page breakage, > e.g. by temporarily retaining a stub implementation of > `document.browsingTopics()` that mimics current behavior when a user has no > topics to return. However, since Topics is not enabled by default for all > users, sites should already be using feature detection, which makes the > risks of breakage low. > > Debuggability > > N/A > > Requires code in //chrome? > > True > > Estimated milestones > > Deprecate in M144 and then remove in M150. > > Currently, ~13% > <https://chromestatus.com/metrics/feature/timeline/popularity/5102> of > page loads use Topics 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 <http://goo.gle/ps-status> with the status of > the API and deprecation plans. > > We will also proactively work toward reducing usage to a low level once > the intent is approved, including disallowing any new enrollment sign-ups, > and contacting all enrolled sites that use the Privacy Sandbox APIs to > inform them about the deprecation timelines. > > Link to entry on the Chrome Platform Status > > https://chromestatus.com/feature/5135370673061888 > > -- 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/c97119d8-b351-4e2d-b106-c7ea1e4f60ccn%40chromium.org.
