On Fri, Aug 14, 2026 at 2:34 AM Anton Bershanskyi <[email protected]>
wrote:

> Hello,
>
> As of writing, the official "Privacy Sandbox feature status" article
> <https://privacysandbox.google.com/overview/status> includes a table
> "Fenced Frames" status as "Continue to support" and then later down lists
> it as "In general availability in Chrome.". The article includes timestamp
> "Last updated: October 17, 2025" so it was written before Fenced Frame API
> specification was archived on GitHub
> <https://github.com/WICG/fenced-frame/commit/1133dcaa93be2d934cfa9c704b4e42875107b550>
> on February 15, 2026. Perhaps, this article could be updated to communicate
> deprecation?
>
Thanks, yes we plan to update the documentation shortly.

>
> Thanks,
> Anton.
> On Thursday, August 13, 2026 at 8:11:33 PM UTC+3 [email protected]
> wrote:
>
>> This answers the question, thank you.
>>
>> Does M154 also come with a deprecation warning or is this just going be a
>> silent stub? I'm curious if there is some forcing function for developers
>> to realize that this is going to be removed in M155?
>>
>> Thanks,
>> Vlad
>>
>> On Thu, Aug 13, 2026 at 12:42 PM Shivani Sharma <[email protected]>
>> wrote:
>>
>>> Yes, the Fenced Frames use counter
>>> <https://chromestatus.com/metrics/webfeature/timeline/popularity/284>
>>> shows usage on approximately 0.07% of page loads.
>>>
>>> Note that this counter tracks the instantiation of the <fencedframe>
>>> element rather than successful navigation. Since the default URL mode (via
>>> new FencedFrameConfig(url)) has always been disabled by default on Stable,
>>> and the navigation APIs (runAdAuction and selectURL) are already stubbed
>>> and being removed (a precondition to FF's stubbing and removal), these
>>> elements can no longer navigate (internal UMA metrics confirms that).
>>>
>>> Regarding the concern about breaking feature detection: Websites cannot
>>> rely solely on the existence of window.HTMLFencedFrameElement to assume
>>> Fenced Frame navigations will succeed. For example, if a user disables the
>>> Privacy Sandbox via Chrome settings, the HTMLFencedFrameElement interface
>>> remains defined on the window, but the APIs to obtain a navigation config
>>> (runAdAuction, selectURL) return null or reject. Websites already must
>>> handle this case gracefully.
>>>
>>> Staged removal via stubs and Finch: If we remove the element completely
>>> immediately, it will resolve to HTMLUnknownElement. This causes it to lose
>>> its default 300x150 sizing, collapsing to 0x0 unless explicitly sized in
>>> CSS. Staging this transition—keeping it as a stub in M154 and rolling out
>>> the element removal via Finch in M155—allows a gradual transition, rather
>>> than risking sudden layout regressions for 100% of Stable users at once.
>>>
>>> Also a correction on the original intent mentioning stubbing the
>>> `fenced-frame-element.config.setSharedStorageContext()` API but that would
>>> not be needed since shared storage removal will remove that (tracking
>>> bug <https://issues.chromium.org/545349630>).
>>>
>>> Please let me know if this answers the question.
>>>
>>> On Wed, Aug 12, 2026 at 11:43 AM Vladimir Levin <[email protected]>
>>> wrote:
>>>
>>>> Do you have use counter numbers by any chance?
>>>
>>>
>>>> I also have some concern about the plan here. Removing the feature but
>>>> keeping the idl as stubs for a release sounds like it would break feature
>>>> detection. Specifically, one could detect that these APIs exist but they do
>>>> nothing. Can you comment on that? I'd almost want to see a faster removal
>>>> after a deprecation period, assuming use counters are low enough.
>>>>
>>>
>>>> Thanks!
>>>> Vlad
>>>>
>>>> On Tuesday, August 11, 2026 at 4:20:44 PM UTC-4 Shivani Sharma wrote:
>>>>
>>>>> *[Adding summary again with formatting since chromestatus formatting
>>>>> didn't work]*
>>>>>
>>>>> *Summary*
>>>>> Fenced frames are nested frames that embed content onto a page without
>>>>> the ability to share data between the fenced frame and its embedder.
>>>>>
>>>>> window.fence APIs include Fenced frames Ads reporting (FFAR) JS APIs
>>>>> that were created for privacy-safe ads reporting from FFs created using
>>>>> Protected Audience and SelectURL and getNestedConfigs() to support PA
>>>>> component ads.
>>>>>
>>>>> This intent is for removing both of these. Fenced frames element
>>>>> removal will be two step as detailed below.
>>>>> With the removal (or stub API replacement) of PA and selectURL, FFs
>>>>> can no longer be navigated and thus it is safe to remove them.
>>>>>
>>>>> Fenced frames are only able to be navigated using the urn:uuid in a
>>>>> FencedFrameConfig[1], which can only be created using the return values
>>>>> from runAdAuction and selectURL. These APIs are being deprecated and
>>>>> removed in M152 as per the following Intent threads: Protected 
>>>>> Audience[2],
>>>>> Shared Storage[3].
>>>>>
>>>>> Plan: Given that the fenced frames element can no longer be navigated,
>>>>> we propose removing the element from the code in the following phases:
>>>>> 1. M154: Keep the fenced frame element and its associated IDL
>>>>> dependencies as stubs. This is to ensure no JS call throws, e.g.calling
>>>>> fenced-frame-element.config.setSharedStorageContext().
>>>>> 2. M154: In the same milestone we will also remove the window.fence
>>>>> APIs completely. Since there is no FF document navigation, these APIs
>>>>> cannot be invoked anymore, so it will be a no-op.
>>>>> 3. M155 Canary/Beta: Begin a controlled rollout of the stub FF HTML
>>>>> element removal via a field trial. Note that removing the element will
>>>>> resolve it to HTMLUnknownElement.
>>>>> At this point we are requesting approvals for all of the above steps.
>>>>> 4. M155 Stable: Assuming there are no regressions or breakage after
>>>>> reaching 1% stable, we will request additional approval for full removal 
>>>>> of
>>>>> the FF element.
>>>>>
>>>>> [1]
>>>>> https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/html/fenced_frame/fenced_frame_config.idl
>>>>>
>>>>> [2]
>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/k_nubsMb97g/m/awPD4IGLBAAJ
>>>>>
>>>>> [3]
>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/uh5Ke6qyegc/m/WFTFnhyJBAAJ
>>>>>
>>>>> On Tue, Aug 11, 2026 at 4:17 PM Chromestatus <
>>>>> [email protected]> wrote:
>>>>>
>>>>>> *Contact emails*
>>>>>> [email protected], [email protected], [email protected]
>>>>>>
>>>>>> *Explainer*
>>>>>> https://github.com/WICG/fenced-frame/blob/master/explainer/README.md
>>>>>>
>>>>>> *Specification*
>>>>>> https://wicg.github.io/fenced-frame
>>>>>>
>>>>>> *Summary*
>>>>>> Fenced frames are nested frames that embed content onto a page
>>>>>> without the ability to share data between the fenced frame and its
>>>>>> embedder. window.fence APIs include Fenced frames Ads reporting (FFAR) JS
>>>>>> APIs that were created for privacy-safe ads reporting from FFs created
>>>>>> using Protected Audience and SelectURL and getNestedConfigs() to support 
>>>>>> PA
>>>>>> component ads. This intent is for removing both of these. Fenced frames
>>>>>> element removal will be two step as detailed below. With the removal (or
>>>>>> stub API replacement) of PA and selectURL, FFs can no longer be navigated
>>>>>> and thus it is safe to remove them. Fenced frames are only able to be
>>>>>> navigated using the urn:uuid in a FencedFrameConfig[1], which can only be
>>>>>> created using the return values from runAdAuction and selectURL. These 
>>>>>> APIs
>>>>>> are being deprecated and removed in M152 as per the following Intent
>>>>>> threads: Protected Audience[2], Shared Storage[3]. Plan: Given that the
>>>>>> fenced frames element can no longer be navigated, we propose removing the
>>>>>> element from the code in the following phases: 1. M154: Keep the fenced
>>>>>> frame element and its associated IDL dependencies as stubs. This is to
>>>>>> ensure no JS call throws, e.g.calling
>>>>>> fenced-frame-element.config.setSharedStorageContext(). 2. M154: In the 
>>>>>> same
>>>>>> milestone we will also remove the window.fence APIs completely. Since 
>>>>>> there
>>>>>> is no FF document navigation, these APIs cannot be invoked anymore, so it
>>>>>> will be a no-op. 3. M155 Canary/Beta: Begin a controlled rollout of the
>>>>>> stub FF HTML element removal via a field trial. Note that removing the
>>>>>> element will resolve it to HTMLUnknownElement. At this point we are
>>>>>> requesting approvals for all of the above steps. 4. M155 Stable: Assuming
>>>>>> there are no regressions or breakage after reaching 1% stable, we will
>>>>>> request additional approval for full removal of the FF element. [1]
>>>>>> https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/html/fenced_frame/fenced_frame_config.idl
>>>>>> [2]
>>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/k_nubsMb97g/m/awPD4IGLBAAJ
>>>>>> [3]
>>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/uh5Ke6qyegc/m/WFTFnhyJBAAJ
>>>>>>
>>>>>> *Blink component*
>>>>>> Blink>FencedFrames
>>>>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EFencedFrames%22>
>>>>>>
>>>>>> *Web Feature ID*
>>>>>> *No information provided*
>>>>>>
>>>>>> *Motivation*
>>>>>> As described in the summary section, since fenced frames are no
>>>>>> longer able to be navigated to a document, once PA and selectURL are
>>>>>> removed, we should also remove FFs API for code health and to remove 
>>>>>> unused
>>>>>> APIs from the web platform.
>>>>>>
>>>>>> *Initial public proposal*
>>>>>> *No information provided*
>>>>>>
>>>>>> *TAG review*
>>>>>> *No information provided*
>>>>>>
>>>>>> *TAG review status*
>>>>>> Not applicable
>>>>>>
>>>>>> *Goals for experimentation*
>>>>>> None
>>>>>>
>>>>>> *Risks*
>>>>>>
>>>>>>
>>>>>> *Interoperability and Compatibility*
>>>>>> Since fenced frames were not implemented by other browser vendors,
>>>>>> there is no interoperability risk. Removing fenced frames is backward
>>>>>> compatible once PA and selectURL have been removed since FFs can then no
>>>>>> longer be navigated to a document. But there may be minor inconsistencies
>>>>>> b/w FF element and HTMLUnknownElement, e.g. their default size so we plan
>>>>>> to keep FF element as a stub and remove the stub via field trial.
>>>>>>
>>>>>> *Gecko*: No signal
>>>>>>
>>>>>> *WebKit*: No signal
>>>>>>
>>>>>> *Web developers*: No signals
>>>>>>
>>>>>> *Other signals*:
>>>>>>
>>>>>> *WebView application risks*
>>>>>>
>>>>>> Does this intent deprecate or change behavior of existing APIs, such
>>>>>> that it has potentially high risk for Android WebView-based applications?
>>>>>> *No information provided*
>>>>>>
>>>>>>
>>>>>> *Debuggability*
>>>>>> We will add an issue to dev tools when FF is converted to a stub
>>>>>> element, whenever a FF element is created, that they will be removed
>>>>>> shortly.
>>>>>>
>>>>>> *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
>>>>>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?*
>>>>>> Yes
>>>>>>
>>>>>>
>>>>>> *Flag name on about://flags*
>>>>>> *No information provided*
>>>>>>
>>>>>> *Finch feature name*
>>>>>> *No information provided*
>>>>>>
>>>>>> *Non-finch justification*
>>>>>> *No information provided*
>>>>>>
>>>>>> *Rollout plan*
>>>>>> Will ship enabled for all users
>>>>>>
>>>>>> *Requires code in //chrome?*
>>>>>> False
>>>>>>
>>>>>> *Tracking bug*
>>>>>> https://issues.chromium.org/538634423
>>>>>>
>>>>>> *Estimated milestones*
>>>>>> Shipping on desktop 154
>>>>>> Shipping on Android 154
>>>>>> Shipping on WebView 154
>>>>>>
>>>>>> *Anticipated spec changes*
>>>>>>
>>>>>> Open questions about a feature may be a source of future web compat
>>>>>> or interop issues. Please list open issues (e.g. links to known github
>>>>>> issues in the project for the feature specification) whose resolution may
>>>>>> introduce web compat/interop risk (e.g., changing to naming or structure 
>>>>>> of
>>>>>> the API in a non-backward-compatible way).
>>>>>> *No information provided*
>>>>>>
>>>>>> *Link to entry on the Chrome Platform Status*
>>>>>>
>>>>>> https://chromestatus.com/feature/6366274495053824?gate=5364408546099200
>>>>>>
>>>>>> This intent message was generated by Chrome Platform Status
>>>>>> <https://chromestatus.com>.
>>>>>>
>>>>>

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