Hi Jérémie,
Yes, this will be true (assuming `HTTP_USER_AGENT` is derived from the
`User-Agent` request header field in whatever backend system you're
working with).
thanks,
Mike
On 9/2/21 1:49 PM, Jérémie Le Pévédic wrote:
While reducing, can you confirm if the HTTP_USER_AGENT variable
available on the backend and navigator.userAgent available in JS will
remain consistent?
Le mercredi 19 mai 2021 à 07:27:48 UTC-4, mike...@chromium.org a écrit :
**
*Hi there blink-dev and Chromium community,*
*
I’d like to give an update on our current thinking and plans
around User-Agent Reduction (née “User Agent Freezing”) and
provide a space for constructive feedback on the plans. For those
looking for concrete timelines or Chrome versions—we’re not quite
there yet—but will update this thread when we feel more confident
on timing. What we can say at this time is that no UA string
changes are coming to the stable channel of Chrome in 2021.
The last major update we had on the topic was approximately a year
ago
<https://groups.google.com/a/chromium.org/g/blink-dev/c/-2JIRNMWJ7s/m/u-YzXjZ8BAAJ>,
where we announced a pause for two reasons: 1) the desire to not
create an inconvenient migration burden on the web ecosystem
during the early days of the COVID pandemic, and 2) to allow us to
ship the User-Agent Client Hints API
<https://web.dev/user-agent-client-hints/>(UA-CH), which is our
proposed replacement for UA string-based content negotiation and
detection.
It took slightly longer than anticipated (due to unforeseen web
compatibility issues
<https://bugs.chromium.org/p/chromium/issues/detail?id=1149575#c2>),
but UA-CH has been shipping and enabled
<https://www.chromestatus.com/feature/5995832180473856>by default
since M89. We’re also starting the roll-out of both Client Hints
Reliability mechanisms (Critical-CH
<https://chromestatus.com/feature/5727177800679424>& ACCEPT_CH
<https://chromestatus.com/feature/5555544540577792>) to address
use cases where hints are needed on the first request and hope for
those features to be enabled in Chrome by default in M91 (note
that some server-side work may need to be done by sites to take
advantage of ACCEPT_CH). We also have proposed some UA-CH API
updates
<https://groups.google.com/a/chromium.org/g/blink-dev/c/dafizBGwWMw/m/72l-1zm6AAAJ>
we would like to prototype and ship.
High-level Plan
We intend to proceed with UA Reduction as follows:
1.
Beginning in M92, start sending deprecation/reduction notices
for the navigator.userAgent, navigator.appVersion, and
navigator.platform getters in the DevTools Issues tab
<https://developer.chrome.com/docs/devtools/issues/>.
2.
In the coming weeks, we will send an Intent to Experiment to
announce an Origin Trial (OT) for sites to opt into a Reduced
UA String so that we can get feedback on the feasibility and
compatibility of our desired end state. We expect to run an OT
for at least 6 months to provide plenty of time for sites to
opt in, test, and provide feedback.
3.
Evaluate feedback from OT partners and the community, and
based on this feedback proceed to Phases 3 through 7 of our
plan (see next section for details), giving the ecosystem
plenty of time to adapt in between them. Otherwise, reconsider
the best course of action depending on feedback.
4.
For sites with complex use cases that require more time for
migration, we aim to offer the ability to extend the current
User-Agent behavior for at least an additional 6 months
(through a reverse Origin Trial).
Proposed changes
We think it's best to roll this out slowly and incrementally in 7
Phases, pending Origin Trial feedback. As mentioned previously, we
hope to publish an update soon on proposed timing and milestones
for each of these Phases:
Reduction Preparation
Phase 1:Warn about accessing navigator.userAgent,
navigator.appVersion, and navigator.platform in DevTools
Phase 2:Launch an Origin Trial for sites to opt into the final
reduced UA string for testing and feedback, for at least 6 months.
Reduction Rollout
Phase 3: Launch a reverse Origin Trial, for instances where a site
may need more time for migration, for at least 6 months.
Phase 4:Ship reduced Chrome MINOR.BUILD.PATCH version (“0.0.0”).
Once rolled-out, the reduced UA string would apply to all page
loads on desktop and mobile OSes that do not opt into the reverse OT.
Phase 5:Begin roll-out of reduced Desktop UA string and
navigator.platform. Once rolled-out, the reduced UA string would
apply to all page loads on desktop OSes that do not opt into the
reverse OT.
Phase 6:Begin roll-out of reduced Android Mobile (and Tablet) UA
string and navigator.platform. Once rolled-out, the reduced UA
string would apply to all page loads on Android that do not opt
into the reverse OT.
Reduction Completion
Phase 7:reverse OT ends and all page loads receive the reduced UA
string.
See the reference page on chromium.org
<https://www.chromium.org/updates/ua-reduction>which details all
the actual User-Agent/navigator.userAgent changes at each phase,
as well as values for navigator.platform and navigator.appVersion.
Note: We have no plans to change the User-Agent string on Android
WebView or Chrome for iOS at this time, but will make public
updates if and when that changes.
We realize that these proposed changes have raised many valid
questions and concerns, and we appreciate the feedback we’ve
gotten thus far. Please keep the feedback coming! As we continue
to discuss the proposal, we ask everyone to be mindful of the
Chromium Code of Conduct
<https://chromium.googlesource.com/chromium/src/+/master/CODE_OF_CONDUCT.md>.
Thanks,
Mike
*
--
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/87ce179a-6dcb-92bf-c2b3-a9e87da409a0%40chromium.org.
