Hi API owners,
FYI: The Shared Storage IDL was accidentally disabled everywhere,
which effectively disabled the API across all channels. Since there
have been no reported breakages, our revised plan is to proceed
directly with complete code removal via a follow-up CL rather than
ramping down via a Finch study. We are looking for LGTMs to move
forward, thanks.
On Tue, Jul 7, 2026 at 1:33 PM Rick Byers <[email protected]> wrote:
LGTM3
On Wed, Jul 1, 2026 at 11:09 AM Chris Harrelson
<[email protected]> wrote:
LGTM2
On Wed, Jul 1, 2026 at 7:33 AM Yoav Weiss (@Shopify)
<[email protected]> wrote:
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
<https://github.com/WICG/shared-storage/blob/main/README.md>
Specification
https://wicg.github.io/shared-storage/
<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:
o
`window.sharedStorage.worklet.addModule()`
o
`window.sharedStorage.createWorklet()`
o
`window.sharedStorage.worklet.run()`/`sharedStorage.run()`
o
`window.sharedStorage.worklet.selectURL()`/`sharedStorage.selectURL()`
o
`window.sharedStorage.set()`
o
`window.sharedStorage.append()`
o
`window.sharedStorage.delete()`
o
`window.sharedStorage.clear()`
o
`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
<https://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
<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.
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/CAOmohSJt%3DHKN-Zo5SX66bqNe1VLcRo9JQ_rD_oLmuMk85bzkdA%40mail.gmail.com
<https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohSJt%3DHKN-Zo5SX66bqNe1VLcRo9JQ_rD_oLmuMk85bzkdA%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%2Bw9ncAjWKdGdPK%3DL-R5%3DNaZJkWLwKZeUKkzxD22_3ggqvg%40mail.gmail.com
<https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw9ncAjWKdGdPK%3DL-R5%3DNaZJkWLwKZeUKkzxD22_3ggqvg%40mail.gmail.com?utm_medium=email&utm_source=footer>.
