> This Intent mentions an OT; was there feedback from developers about the utility of x-origin iframe pre-rendering? Yes, one of our customers shows significant performance improvement(68%!) on speculative loading with this feature.
> Did we learn anything about the potential risks (e.g., to metrics and privacy)? No report from OT attendees so far. 2026年10月22日(木) 0:24 Alex Russell <[email protected]>: > Do we have a sense for which sorts of applications will benefit from this > change? This Intent mentions an OT; was there feedback from developers > about the utility of x-origin iframe pre-rendering? Did we learn anything > about the potential risks (e.g., to metrics and privacy)? > > Thanks, > > Alex > > On Wednesday, October 14, 2026 at 11:28:21 PM UTC-7 Chromestatus wrote: > >> *Contact emails* >> [email protected] >> >> *Explainer* >> >> https://github.com/WICG/nav-speculation/blob/main/prerendering-cross-origin-iframes.md >> >> *Specification* >> https://wicg.github.io/nav-speculation/prerendering.html >> >> *Summary* >> Prerenders cross-origin iframes with an opt-in response header. Browsers >> will now prerender all cross-origin frames if the top-level frame's HTTP >> response includes the Supports-Loading-Mode: prerender-cross-origin-frames. >> >> *Blink component* >> Blink >> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%22> >> >> *Web Feature ID* >> speculation-rules <https://webstatus.dev/features/speculation-rules> >> >> *Motivation* >> By default, navigational prerendering delays the loading of all >> cross-origin iframes until the referring page activates the prerendered >> page. However, there are some cases where cross-origin iframes are >> particularly important to an application, such that delaying them negates >> many of the benefits of prerendering. >> >> *Initial public proposal* >> >> https://groups.google.com/a/chromium.org/g/blink-dev/c/KP1f2UTqCgM/m/q_EQ5ceXHgAJ >> >> *TAG review* >> https://github.com/w3ctag/design-reviews/issues/1207 >> >> *TAG review status* >> Issues addressed >> >> *Origin Trial Name* >> Prerendering cross-origin iframes >> >> *Goals for experimentation* >> Gather feedback from web authors who already are interested in this >> feature. >> >> *Chromium Trial Name* >> Prerender2CrossOriginIframes >> >> *Origin Trial documentation link* >> >> https://github.com/WICG/nav-speculation/blob/main/prerendering-cross-origin-iframes.md >> >> *WebFeature UseCounter name* >> kPrerender2CrossOriginIframes >> >> *Risks* >> >> >> *Interoperability and Compatibility* >> The entire speculative loading feature is a progressive enhancement, so >> in general risks are low in this area. >> >> *Gecko*: No signal ( >> https://github.com/mozilla/standards-positions/issues/1376) No signal as >> of 2026-10-15 >> >> *WebKit*: No signal ( >> https://github.com/WebKit/standards-positions/issues/636) No signal as >> of 2026-10-15 >> >> *Web developers*: Positive Our partners have given positive feedback on >> this feature. >> >> *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. >> >> >> *Debuggability* >> The cross-origin iframe prerendering should be debuggable as well as top >> frame's one: >> https://developer.chrome.com/docs/devtools/application/debugging-speculation-rules#prerender >> >> *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>?* >> Yes >> >> >> *Flag name on about://flags* >> "prerender2-cross-origin-iframes" from M148 >> >> *Finch feature name* >> Prerender2CrossOriginIframes >> >> *Rollout plan* >> Will ship enabled for all users >> >> *Requires code in //chrome?* >> False >> >> *Tracking bug* >> https://issues.chromium.org/issues/440387014 >> >> *Availability expectation* >> Feature is available only in Chromium browsers for the foreseeable future. >> >> *Adoption expectation* >> Feature is used by specific partner(s) to provide functionality within 12 >> months of launch in Chrome. >> >> *Adoption plan* >> One of our partners has already joined in origin trial in Chrome and >> shows better performance result. >> >> *Non-OSS dependencies* >> >> Does the feature depend on any code or APIs outside the Chromium open >> source repository and its open-source dependencies to function? >> No. >> >> *Estimated milestones* >> Shipping on desktop 158 >> Origin trial desktop first 147 >> Origin trial desktop last 152 >> Origin trial extension 1 end milestone 158 >> Shipping on Android 158 >> Shipping on WebView 158 >> Shipping on iOS 158 >> >> *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). >> *No information provided* >> >> *Link to entry on the Chrome Platform Status* >> https://chromestatus.com/feature/5112398709129216?gate=5121426126405632 >> >> *Links to previous Intent discussions* >> Intent to Prototype: >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68b670ba.050a0220.270bc4.0593.GAE%40google.com >> Intent to Experiment: >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAAEV3p%3DzhNhfOpe8x%3DRKgxYFS9GCq_q-c8knZYRBRuijQ27o8w%40mail.gmail.com >> Intent to Extend Experiment 1: >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6a45fcf5.198129d7.1d0cd0.0014.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. 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