LGTM1 On Tue, Jan 17, 2023 at 8:02 AM Victor Tan <victor...@chromium.org> wrote:
> Contact emails > > victor...@chromium.org, miketa...@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% 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 and plan to do for Phase 5 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 6 of the User-Agent Reduction plan > <https://www.chromium.org/updates/ua-reduction/#sample-ua-strings-phase-6>. > In Phase 6, we change the deviceModel token to “K” and change the > androidVersion token to a static “10” string in Android User-Agent > string. The navigator.platform will be a “Linux armv81” constant on the > Android platform. > > Blink component > > Blink>Network>ClientHints > > TAG review > > https://github.com/w3ctag/design-reviews/issues/640 > > TAG review status > > Closed satisfied with concerns. > > Risks > Interoperability and Compatibility > > Any time you modify the User-Agent string there is a risk of breaking > existing patterns, like some content somewhere depending on the previous > format. > > We do not expect interoperability risks, as each browser sends its own > User-Agent string format. However there is a risk that - on the Android > platform - content may rely on User-Agents to parse deviceModel and > androidVersion information. To mitigate the risk of this change, we intend > to slowly roll out the format via Finch on the Android platform and observe > health metrics and bug reports. See timeline below on our slow roll out > plan. This gives us the option to roll this back for the Android platform > if major issues arise. > > Displaying a static androidVersion and a deviceModel token for Android > clients will not create a problem syntactically. But the web can get pretty > weird in ways we don't anticipate. For example, sites can rely on the > deviceModel in the User-Agent string to determine whether the device is a > mobile, laptop or desktop. Currently, we change the deviceModel to a static > string, sites need to use client hints as the alternative to determine the > right behavior. Hence the slow roll-out and incremental path towards > User-Agent Reduction. > > Here is our proposed rollout plan in Chrome Stable channel > (Canary/Dev/Beta has been enabled 50%), 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 > > Duration > > Date > > Stable 1% (M110+) > > M110 stable release is shipping to 100% (a best guess) > > Feb 14, 2023 > > Stable 10% (M110/M111) > > ~4 weeks after previous stage > > Mar 14, 2023 > > Stable 50% > > (M110/M111) > > ~2 weeks > > Mar 28, 2023 > > TOT Default (M114) > > ~2 weeks after previous stage > > Apr 11, 2023 > > Stable 100% (M110=>M114) > > ~ Same business day as previous stage > > Apr 11, 2023 > > Web stakeholders can still test with the user agent reduction deprecation > origin trial > <https://developer.chrome.com/origintrials/#/view_trial/2608710084154359809> > until M113 (late May) if they need more time to adapt to the coming > changes. The UA-RD OT allows web stakeholders to request the legacy > user-agent string values (i.e. non-reduced values). > > 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. Also, UA reduction > phase 6 will only apply to the Android platform. > > Web developers: Mixed signals. Various channels have different reactions. > It’s similar for the UA reduction phase 4 and phase 5. > > > 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 Android) > > Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md> > ? > > No, because User-Agents vary across browsers. > > Flag name > > #reduce-user-agent-android-version-device-model > > Notes: The existing flag #reduce-user-agent will provide the same format > User-Agent string on the Android platform since this is the last phase for > User-Agent reduction. > > Tracking bug > > https://bugs.chromium.org/p/chromium/issues/detail?id=1394819 > > Launch bug > > https://launch.corp.google.com/launch/4225291 > > Link to entry on the Chrome Platform Status > > https://chromestatus.com/feature/5177681979637760 > > -- > 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/CAJh4P7F7jKA4985JjpdzTr_XDkP%3DfS2pKaoBMStad9%3DujUzjuw%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJh4P7F7jKA4985JjpdzTr_XDkP%3DfS2pKaoBMStad9%3DujUzjuw%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 blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw-zjUXrC9m2mfPQXDrQUnqBbUGUSsrZUhVJDPxcFD%3DZhA%40mail.gmail.com.
