LGTM2
On 3/31/26 6:46 a.m., Yoshisato Yanagisawa wrote:
Let me share the summary of origin trials as Yoav asked:
Currently, 35 sites, including large and medium-scale origins,
participated in the origin trials. Usage metrics can be found at
https://chromestatus.com/metrics/feature/timeline/popularity/5550.
Developers expressed strong interest in using this feature to maintain
a SharedWorker's lifetime across same-origin navigations within a
single tab. While there were requests for seamless migration from
non-extended to extended lifetime workers, we identified a potential
"footgun" regarding WebLocks where a long-lived worker could hold a
lock indefinitely. To ensure safety, we decided to enforce strict
separation between the two lifetime modes.
Feedback also showed that the feature effectively handles asynchronous
tasks after a page unloads in most scenarios. However, some sites with
strict Content Security Policies (CSP) encountered issues when using
the feature with blob: URLs.
Notably, extended lifetime shared workers were successfully integrated
into the HTML standard during the OT period, with positive signals
from other browser vendors. Additionally, as we are working on
enabling SharedWorker on Android (as discussed in a separate thread),
this feature will also be available on Android following that rollout.
To improve observability, chrome://inspect/#workers was updated to
indicate whether a SharedWorker is running with the extendedLifetime flag.
Please let me know if you have any questions.
2026年3月31日(火) 18:22 Yoav Weiss (@Shopify) <[email protected]>:
LGTM1
On Tue, Mar 31, 2026 at 8:09 AM Chromestatus
<[email protected]> wrote:
*Contact emails*
[email protected], [email protected]
*Explainer*
https://gist.github.com/domenic/c5bd38339f33b49120ae11b3b4af5b9b#file-1-explainer-md
*Specification*
https://github.com/whatwg/html/commit/9c009049e4fa9dba638ef68ca502b781082bbb68
https://github.com/whatwg/html/pull/11600 is a slightly more
convenient link.
*Summary*
This update adds a new option, `extendedLifetime: true`, to
the `SharedWorker` constructor. This requests that the shared
worker be kept alive even after all current clients have
unloaded. The primary use case is to allow pages to perform
asynchronous work that requires JavaScript after a page
unloads, without needing to rely on a service worker.
*Blink component*
Blink>Workers
<https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWorkers%22>
*Web Feature ID*
shared-workers <https://webstatus.dev/features/shared-workers>
*Motivation*
Many sites want to perform some work during document
unloading. This usually includes writing to storage, or
sending information to severs. Currently, if this work is done
asynchronously (e.g., writing to IndexedDB instead of
localStorage, or using CompressionStream to compress the body
before sending a fetch()) the only way to do this is to use a
service worker. However, requiring a service worker for this
simple case of work-after-unload is heavyweight: the disk
space, memory consumption, and developer experience of
managing the service worker registration and lifecycle makes
this hard to deploy. By using shared workers, all of these
downsides are avoided.
*Initial public proposal*
https://github.com/whatwg/html/issues/10997
*TAG review*
https://github.com/w3ctag/design-reviews/issues/1089
*TAG review status*
Pending
*Origin Trial Name*
Extended lifetime shared workers
*Goals for experimentation*
None
*Chromium Trial Name*
SharedWorkerExtendedLifetime
*Origin Trial documentation link*
https://gist.github.com/domenic/c5bd38339f33b49120ae11b3b4af5b9b#file-1-explainer-md
*WebFeature UseCounter name*
kSharedWorkerExtendedLifetimeFeatureEnabled
*Risks*
*Interoperability and Compatibility*
We intend to specify that the lifetime timeout for these
shared workers be extended in the same way as service workers.
Because the exact timeout of service workers is left
implementation-defined, it's possible that code using this new
feature could be non-interoperable. However, this has so far
not proved to be a major problem in practice for service workers.
/Gecko/:
Positive (https://github.com/mozilla/standards-positions/issues/1227)
Some
unofficial tentative positive signals and engagement in the
proposal issue.
/WebKit/: No
signal (https://github.com/WebKit/standards-positions/issues/492) Some
unofficial tentative negative signals in the proposal issue.
It'd be good to update that thread with OT results, as discussed.
/Web developers/: Positive The problem of wanting to perform
asynchronous work during unload is well-known, with the
service worker workaround currently deployed, including by
Google properties.
/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*
The chrome://inspect/#workers page indicates when a
SharedWorker is using the extendedLifetime option.
*Will this feature be supported on all six Blink platforms
(Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?*
No
Shared workers are not yet supported on Android and Android
WebView. However, we are concurrently working on enabling them
there, and when we do, this feature will also be supported.
*Is this feature fully tested by web-platform-tests
<https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?*
Yes
https://wpt.fyi/results/workers/tentative/SharedWorker-extendedLifetime.html
*Flag name on about://flags*
/No information provided/
*Finch feature name*
SharedWorkerExtendedLifetime
*Rollout plan*
Will ship enabled for all users
*Requires code in //chrome?*
False
*Tracking bug*
https://issues.chromium.org/issues/400473072
*Estimated milestones*
Shipping on desktop 148
Origin trial desktop first 139
Origin trial desktop last 142
Origin trial extension 1 end milestone 145
Origin trial extension 2 end milestone 148
Shipping on Android 148
Shipping on WebView 148
*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).
We are currently discussing some details in preparation for
specification. The exact nature of how the lifetime extension
works with regard to non-window clients, particularly, has
only recently reached a tentative conclusion.
*Link to entry on the Chrome Platform Status*
https://chromestatus.com/feature/5138641357373440?gate=4686145547665408
*Links to previous Intent discussions*
Intent to Experiment:
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6862683f.170a0220.16d1bf.0122.GAE%40google.com
Intent to Extend Experiment 1:
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68de2b1f.050a0220.58465.05c2.GAE%40google.com
Intent to Extend Experiment 2:
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/69704662.2b0a0220.2c228a.0283.GAE%40google.com
This intent message was generated by Chrome Platform Status
<https://chromestatus.com>.
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