domenic@ found the place in HTML spec that already mentioned this header for prefetch: Fetch Standard <https://fetch.spec.whatwg.org/#:~:text=If%20httpRequest%E2%80%99s%20initiator%20is%20%22prefetch%22%2C%20then%20set%20a%20structured%20field%20value%20given%20(%60Sec%2DPurpose%60%2C%20the%20token%20prefetch)%20in%20httpRequest%E2%80%99s%20header%20list>
Positive for Mozilla as they've already mainly migrated to using the header, and not planned for Webkit and they don't support rel=prefetch. On Monday, May 12, 2025 at 7:45:16 AM UTC-7 Steven Wei wrote: > Thanks! Added an issue to whatwg/html repo: Can we include what > header(s) get sent with link type prefetch? · Issue #11294 · whatwg/html > <https://github.com/whatwg/html/issues/11294> > Also, I don't think Safari supports <link rel=prefetch>. > > Also, started vendor position requests: > Mozilla: Send Sec-Purpose header for link type prefetch (rel=prefetch) · > Issue #1228 · mozilla/standards-positions > <https://github.com/mozilla/standards-positions/issues/1228> > Webkit: Send Sec-Purpose header for link type prefetch (rel=prefetch) · > Issue #493 · WebKit/standards-positions > <https://github.com/WebKit/standards-positions/issues/493> > > On Thursday, May 8, 2025 at 2:30:17 PM UTC-7 yoav...@chromium.org wrote: > > On Thu, May 8, 2025 at 11:11 PM Chromestatus < > ad...@cr-status.appspotmail.com> wrote: > > Contact emails stev...@microsoft.com > > Explainer https://github.com/w3c/resource-hints/issues/74 > > Specification > https://chromium-review.googlesource.com/c/chromium/src/+/6334746 > > > That's not a specification. Is it possible to file an issue on HTML and > try to bake that into the standard? > > > > Summary > > Chrome currently passes both 'Purpose: prefetch' and 'Sec-Purpose: > prefetch' headers as part of prefetch through speculation rules. However, > only 'Purpose: prefetch' is passed with <link rel=prefetch>. We plan to > standardize this header for both speculation rules and <link rel=prefetch> > by adding 'Sec-Purpose: prefetch' header to the latter. Future work will > involve stop sending 'Purpose: prefetch' for prefetches, prerenders, etc. > > > Blink component Blink>Loader > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ELoader%22> > > > TAG review Not filed as this is a minor change of unspec'ed UA behavior > for an existing feature. (Can start a review if recommended) > > TAG review status Pending > > Risks > > > Interoperability and Compatibility > > As commented at notes on Firefox and Safari, each browser uses > non-standardized header name that is not aligned with CORS spec. This > change will introduce better interoperability and compatibility for a long > term. > > > *Gecko*: No signal Firefox has sent ‘X-moz: prefetch’. > > *WebKit*: No signal Safari has sent 'Purpose: prefetch' but changed to > use 'X-Purpose: preview'. > > > Can you open vendor position requests and try to get them on board this > change? > > Also, does Safari support <link rel=prefeftch>? Or is that for URL bar > driven prefetches? > > > > *Web developers*: No signals > > > With my web developer hat on, these different headers are definitely a > hurdle and can cause some prefetches to be missed. > > > > > *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? > > None > > > Debuggability > > > > Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)? No > > Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> > ? No > > Plan to add a new test. > > > Flag name on about://flags None > > Finch feature name None > > Non-finch justification None > > Rollout plan Will ship enabled for all users > > Requires code in //chrome? False > > Tracking bug https://issues.chromium.org/issues/40236973 > > Estimated milestones > > No milestones specified > > > 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). > None > > Link to entry on the Chrome Platform Status > https://chromestatus.com/feature/6247959677108224?gate=4656924191096832 > > Links to previous Intent discussions Intent to Prototype: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/680fb6c9.050a0220.1699c.03f6.GAE%40google.com > > > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com>. > > -- > 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+...@chromium.org. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/681d1e1b.050a0220.d6048.0024.GAE%40google.com > > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/681d1e1b.050a0220.d6048.0024.GAE%40google.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 visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/70f2338a-168f-4747-be74-2784fb90f436n%40chromium.org.
