Contact emails miketa...@chromium.org, victor...@chromium.org
Explainer https://github.com/WICG/ua-client-hints#explainer-reducing-user-agent-granularity Specification https://www.chromium.org/updates/ua-reduction is the closest thing that specifies Chrome’s UA Reduction plans today. As these changes land in Chromium and ship to 100% of stable, the Compat Standard <https://compat.spec.whatwg.org/> will be updated in the UA String section <https://compat.spec.whatwg.org/#ua-string-pattern-chrome>, like we did for the Phase 4 changes. Summary As previously detailed on the Chromium Blog <https://blog.chromium.org/2021/09/user-agent-reduction-origin-trial-and-dates.html>, we intend to proceed with Phase 5 of the User-Agent Reduction plan <https://www.chromium.org/updates/ua-reduction/#sample-ua-strings-phase-5>. In Phase 5, the User-Agent string changes the platform and oscpu tokens from their platform-defined values to the relevant unifiedPlatform <https://www.chromium.org/updates/ua-reduction/#token-reference> token value. The `navigator.platform`, `navigator.platform`, and `navigator.appVersion` JS APIs will be similarly reduced. Blink component Blink>Network>ClientHints TAG review https://github.com/w3ctag/design-reviews/issues/640 TAG review status Closed with concerns. Risks Interoperability and Compatibility Any time you modify the User-Agent string there is a risk of some content somewhere depending on the previous format. We do not expect interop risks, as each browser sends its own User-Agent string format. But there is a risk, especially on legacy Windows platforms, that content somewhere is relying on User-Agents to parse platform and oscpu information. We believe the risk is somewhat low. But in order to mitigate the risk of this change, we intend to slowly roll it out via Finch creating two sub groups: one group enabling the feature for all platforms except legacy Windows platforms, another group enabling the feature on legacy Windows platforms and observing health metrics and bug reports. This gives us the option to roll this back specifically for legacy Windows clients if needed, but proceed for other platforms. Displaying a modern OS version for legacy clients will not create a problem syntactically on legacy Windows platforms. But the web can get pretty weird in ways we don't anticipate, hence the slow roll-out and incremental path towards User-Agent Reduction. Here is our proposed rollout plan, with the understanding that if we discover concerning breakage or regressions via health metrics or bug reports we will pause the rollout or roll back the feature entirely (and update this thread if so): Stage Time Date Stable 1% (M107+) Canary/Dev/Beta 100% M107 stable release is shipping to 100% (a best guess) Nov 1, 2022 Stable 10% (M107/M108/M109) ~10 weeks after previous stage Jan 9, 2022 Stable 50% (M107/M108/M109) ~2 weeks Jan 23, 2022 TOT Default (M111) ~2 weeks after previous stage Feb 7, 2022 Stable 100% (M107=>M111) ~ Same business day as previous stage Feb 7, 2022 Gecko: Shipped/Shipping. Firefox has frozen (or capped) much of their UA string already. WebKit: Shipped/Shipping. Safari has already frozen everything in their desktop UA string except for Safari and WebKit versions. Web developers: Mixed signals. Reactions have ranged from positive to indifferent to negative, from various channels. Debuggability No special DevTools support needed. Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)? No (Only for desktop platforms: Windows, Mac, Linux, Chrome OS) Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md> ? No Flag name #reduce-user-agent-platform-oscpu Tracking bug https://bugs.chromium.org/p/chromium/issues/detail?id=1339834 Launch bug https://bugs.chromium.org/p/chromium/issues/detail?id=1346071 Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5098783126323200 -- 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 blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJh4P7FysJS2D2i4G3YNkf6X8N4_eyUcP%2BpoFrUB_ikdiATwuA%40mail.gmail.com.
