LGTM1 On Fri, Jun 12, 2026 at 12:49 AM Cammie Smith Barnes <[email protected]> wrote:
> Hi API Owners, > > The Shared Storage API was deprecated in Chrome-144 with a plan to remove > it in Chrome-150. For example, currently the usage of > sharedStorage.worklet.addModue() is at 3.1% of page loads. > > <https://chromestatus.com/metrics/feature/timeline/popularity/4264>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, > > Cammie > > > On Wed, Nov 19, 2025 at 11:13 AM Chris Harrelson <[email protected]> > wrote: > >> LGTM3 >> >> On Wed, Nov 19, 2025 at 8:12 AM Vladimir Levin <[email protected]> >> wrote: >> >>> LGTM2 with the same conditions as Yoav >>> >>> On Wednesday, November 19, 2025 at 11:11:12 AM UTC-5 Yoav Weiss wrote: >>> >>>> LGTM1 to carry on with deprecation in M144 and to remove in M150 IFF >>>> usage is lower than 0.0003% >>>> >>>> In case usage doesn't drop as M150 approaches, I expect y'all to come >>>> back to this thread so that we can jointly evaluate our options. Does that >>>> work? >>>> >>>> On Friday, November 14, 2025 at 7:43:00 PM UTC+1 Cammie Smith Barnes >>>> wrote: >>>> >>>>> Thank you for raising this issue. >>>>> >>>>> We've already reached out to folks representing 99% of the remaining >>>>> Shared Storage API calls, and will reach out to the rest soon. We're >>>>> confident that we can remove this API by the proposed milestone with >>>>> minimal user breakage or utility loss. >>>>> >>>>> Cammie >>>>> >>>>> On Wed, Nov 12, 2025 at 11:42 AM Daniel Bratell <[email protected]> >>>>> wrote: >>>>> >>>>>> Part of the reason that I think that we can remove the other "privacy >>>>>> sandbox" features so aggressively despite high usage numbers, is that the >>>>>> number of actual users is very limited. I don't have the understanding >>>>>> necessary to say if that is true for this one as well. >>>>>> >>>>>> Or in other words, do you know how realistic it is to drive this to a >>>>>> really, really, minute usage number through a deprecation? >>>>>> >>>>>> I am also more worried about the effect of breaking this compared to >>>>>> some of the others. It seems more likely to actually cause site breakage, >>>>>> if (I don't know this) it is used more widely than the other APIs. >>>>>> >>>>>> Do you know more about those concerns? >>>>>> >>>>>> /Daniel >>>>>> On 2025-11-07 20:32, Cammie Smith Barnes wrote: >>>>>> >>>>>> Intent to deprecate and remove Shared Storage >>>>>> >>>>>> >>>>>> Contact emails >>>>>> >>>>>> [email protected] >>>>>> >>>>>> Explainer >>>>>> >>>>>> https://github.com/WICG/shared-storage/blob/main/README.md >>>>>> >>>>>> Specification >>>>>> >>>>>> https://wicg.github.io/shared-storage/ >>>>>> >>>>>> Summary >>>>>> >>>>>> The Shared Storage API is a privacy-preserving web API to enable >>>>>> storage that is not partitioned by first-party site. >>>>>> >>>>>> 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 the Shared Storage API (along with >>>>>> certain >>>>>> other Privacy Sandbox APIs, as outlined on the Privacy Sandbox >>>>>> feature status page >>>>>> <https://privacysandbox.google.com/overview/status>). >>>>>> >>>>>> Interest in the Shared Storage API has decreased since the >>>>>> announcement. Use of sharedStorage.worklet.addModule() >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4264> >>>>>> has decreased ~20% from its peak of 7.35% of page loads down to 5.85% of >>>>>> page loads. Use of sharedStorage.createWorklet() >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4836> >>>>>> has decreased ~82% from 4.87% to 0.864% of page loads. Use of >>>>>> sharedStorage.run() >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4270> >>>>>> has decreased ~30% from 5.28% to 3.71% of page loads. Use of >>>>>> sharedStorage.selectURL() >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4269> >>>>>> has decreased ~28% from 6.24% to 4.51% of page loads. Use of >>>>>> sharedStorage overall >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4263> >>>>>> has decreased ~9% from 11.91% of page loads to 10.86% of page loads. >>>>>> >>>>>> Blink component >>>>>> >>>>>> Blink>Storage>SharedStorage >>>>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EStorage%3ESharedStorage%22> >>>>>> >>>>>> Web Feature ID >>>>>> >>>>>> None >>>>>> >>>>>> Motivation >>>>>> >>>>>> Chrome has announced >>>>>> <https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/> >>>>>> that the current approach to third-party cookies will be maintained. >>>>>> Given >>>>>> this, we expect adoption to decrease over time (currently at ~11% >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4263> >>>>>> of page loads) as the main use cases for Shared Storage 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. >>>>>> >>>>>> >>>>>> Developer-facing impact >>>>>> >>>>>> Sites that are using the Shared Storage API that do not migrate to >>>>>> alternative solutions may experience a disruption in functionality, and >>>>>> in >>>>>> particular all writes, reads, and worklet operations will fail. If >>>>>> continued usage numbers warrant, we will take steps to minimize any risk >>>>>> of >>>>>> actual page breakage, e.g. by temporarily retaining stub implementations >>>>>> of >>>>>> the window-exposed methods that are still being called most frequently. >>>>>> >>>>>> The following API surfaces will be removed: >>>>>> >>>>>> - >>>>>> >>>>>> All of the Shared Storage JavaScript functions exposed to the >>>>>> Window >>>>>> >>>>>> <https://github.com/WICG/shared-storage/blob/main/README.md#outside-of-worklets-eg-places-where-writing-can-happen> >>>>>> will be removed or replaced with stub implementations: >>>>>> - >>>>>> >>>>>> `window.sharedStorage.worklet.addModule()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.createWorklet()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.worklet.run()`/`sharedStorage.run()` >>>>>> - >>>>>> >>>>>> >>>>>> >>>>>> `window.sharedStorage.worklet.selectURL()`/`sharedStorage.selectURL()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.set()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.append()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.delete()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.clear()` >>>>>> - >>>>>> >>>>>> `window.sharedStorage.batchUpdate()` >>>>>> - >>>>>> >>>>>> All of the Shared Storage JavaScript functions exposed only to >>>>>> the SharedStorageWorklet >>>>>> >>>>>> <https://github.com/WICG/shared-storage/blob/main/README.md#in-the-worklet-during-an-operation> >>>>>> will be removed. Since the worklet operation methods >>>>>> (`sharedStorage.run()` >>>>>> and `sharedStorage.selectURL()` listed above) will be removed or >>>>>> replaced >>>>>> with no-op stub implementations, there will be no calls to any >>>>>> SharedStorageWorklet-exposed Shared Storage JavaScript functions, and >>>>>> so >>>>>> removing them will cause no breakage. >>>>>> - >>>>>> >>>>>> The SharedStorageWorklet interface will be removed or replaced by >>>>>> a stub worklet interface (potentially for `addModule`, `run`, >>>>>> `selectURL` >>>>>> stub implementations). >>>>>> - >>>>>> >>>>>> Consequently the `sharedStorage.worklet` attribute will either be >>>>>> removed or updated to the stub worklet interface type pending removal. >>>>>> - >>>>>> >>>>>> The `sharedStorage.context` attribute will be removed, along with >>>>>> the related `setSharedStorageContext()` method on fenced frame >>>>>> configs. We >>>>>> will measure the usage of `setSharedStorageContext()` to determine >>>>>> whether >>>>>> it should be replaced with a no-op stub implementation instead. >>>>>> - >>>>>> >>>>>> The `sharedstoragewritable` attribute on <iframe> and <img> >>>>>> elements will be ignored. >>>>>> - >>>>>> >>>>>> The `sharedStorageWritable` option in the fetch() API's >>>>>> RequestInit will be a no-op. >>>>>> - >>>>>> >>>>>> Consequently, the `Sec-Shared-Storage-Writable` and >>>>>> `Sec-Shared-Storage-Data-Origin` request headers will no longer be >>>>>> sent, >>>>>> and the `Shared-Storage-Write` and >>>>>> `Shared-Storage-Cross-Origin-Worklet-Allowed` response headers will no >>>>>> longer be honored. >>>>>> - >>>>>> >>>>>> The “shared-storage” and “shared-storage-select-url” permissions >>>>>> policy-controlled features will be removed along with the APIs. Since >>>>>> the >>>>>> APIs they control will no longer exist, the permission policies will >>>>>> have >>>>>> no effect and their removal is not considered a breaking change. >>>>>> - >>>>>> >>>>>> The `sharedStorage` attribute on the Window will be removed once >>>>>> all stub implementations are no longer needed and are removed. >>>>>> >>>>>> >>>>>> Estimated milestones >>>>>> >>>>>> Planning to deprecate in M144 and remove in M150. >>>>>> >>>>>> Currently, ~11% >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4263> >>>>>> of page loads use Shared Storage API. While this usage is quite high >>>>>> for a deprecation and removal, it is driven by a small number of >>>>>> third-party ad tech scripts present on a large number of sites. We will >>>>>> continue to monitor usage in addition to providing comprehensive updates >>>>>> on >>>>>> privacysandbox.google.com with the status of the API and deprecation >>>>>> plans <https://privacysandbox.google.com/overview/status>. >>>>>> >>>>>> We will 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. >>>>>> >>>>>> Link to entry on the Chrome Platform Status >>>>>> >>>>>> https://chromestatus.com/feature/5076349064708096 >>>>>> >>>>>> -- >>>>>> 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/CAJ8xcq6ty%3DiW_L9%3DpbzJbZKAT7rVdu_%2B9-QJ2P2ojCRtSRk4xw%40mail.gmail.com >>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJ8xcq6ty%3DiW_L9%3DpbzJbZKAT7rVdu_%2B9-QJ2P2ojCRtSRk4xw%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/a54fca7f-06d9-4e5c-b15c-3f6cf408b0bbn%40chromium.org >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/a54fca7f-06d9-4e5c-b15c-3f6cf408b0bbn%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/CAJ8xcq671i84KCqC1wOkwLAMVtZu7%2BvfbH8yEhRMU3ZU6%2B11rA%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJ8xcq671i84KCqC1wOkwLAMVtZu7%2BvfbH8yEhRMU3ZU6%2B11rA%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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