On Tuesday, June 9, 2026 at 6:22:10 AM UTC+2 Chromestatus wrote:
*Contact emails* [email protected] *Explainer* https://github.com/WICG/nav-speculation/blob/main/ prerendering-form-submission.md Am I correct to assume that this only works for GET based form submissions? *Specification* https://storage.googleapis.com/spec-previews/WICG/nav- speculation/pull/426/diff/prerendering.html *Design docs* https://docs.google.com/document/d/13Xr_kSYZtvhRNaKpCiP7wLKYtDcpLdDWSH 4y6gHq0kQ/edit?usp=sharing *Summary* This extends speculation rules syntax to allow developers to specify the form_submission field for prerender. This field directs the browser to prepare the prerender as a form submission, so that it can be activated by real form submission navigations. Examples include a simple search form which results in a /search?q=XXX GET request navigation, support of which has been requested by web developers. *Blink component* Internals>Preload>Prerender <https://issues.chromium.org/issues?q=customfield1222907:%22Internals%3EPreload%3EPrerender%22> *Web Feature ID* speculation-rules <https://webstatus.dev/features/speculation-rules> *Motivation* Form submissions cannot activate prerendered pages currently by design, due to internal browser limitations. In at least Chrome, ordinary form submission navigations have special state and run extra checks that ordinary prerenders don't experience. This means that a form submission can never activate a prerender, because the prerender was not prepared properly as a form submission. In addition to the internal browser limitations, resources can be wasted on prerendering a page which is not eligible, such as CSP disallowing form-action. *Initial public proposal* https://github.com/WICG/nav-speculation/issues/322 *TAG review* https://github.com/w3ctag/design-reviews/issues/1192 *TAG review status* Issues addressed *Origin Trial Name* PrerenderActivationByFormSubmission *Goals for experimentation* To evaluate how the prerendering form_submission support works on real sites before shipping it by default. We will be evaluating performance, stability, and correctness, and any other feedback the sites have when they use this feature. *Chromium Trial Name* PrerenderActivationByFormSubmission *Origin Trial documentation link* https://github.com/WICG/nav-speculation/blob/main/ prerendering-form-submission.md *WebFeature UseCounter name* kPrerenderActivationByFormSubmission *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/1355) Mozilla is neutral on speculation rules syntax in general ( https://github.com/mozilla/standards-positions/issues/620), although positive on prefetching. This new request for this specific feature is still pending for new response after pinging. *WebKit*: No signal (https://github.com/WebKit/standards-positions/ issues/614) WebKit has not yet responded to our 2022 request for a position on speculation rules although positive on same-origin prefetching. ( https://github.com/WebKit/standards-positions/issues/54) We opened a new request for this specific feature to ensure we captured any of their input. *Web developers*: Positive (https://github.com/WICG/nav-speculation/issues/ 322) *Other signals*: *Ergonomics* No *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, speculation rules prerender are not supported on WebView. *Debuggability* As well as other speculationrule features, this feature can be viewed on devtools as the source script. Another dedicated field will be added to the panel for easier debugging. *Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?* No Windows, Mac, Linux, ChromeOS, Android. WebView doesn't support speculation rules prerendering because prerendering navigation breaks the lifecycle (e.g., callback sequence) of the WebView. *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* PrerenderActivationByFormSubmission *Finch feature name* PrerenderActivationByFormSubmission *Rollout plan* Will ship enabled for all users *Requires code in //chrome?* False *Tracking bug* https://issues.chromium.org/issues/346555939 *Measurement* Blink.UseCounter.Features https://crrev.com/c/7533307 *Estimated milestones* Shipping on desktop151 Origin trial desktop first146 Origin trial desktop last151 DevTrial on desktop146 Shipping on Android151 Origin trial Android first146 Origin trial Android last151 DevTrial on Android146 *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/5074313831120896?gate=6571193366872064 *Links to previous Intent discussions* Intent to Prototype: https://groups.google.com/a/chromium.org/d/msgid/blink- dev/698f0243.2b0a0220.19817b.0194.GAE%40google.com Intent to Experiment: https://groups.google.com/a/ chromium.org/d/msgid/blink-dev/69aa2f3b.2b0a0220.c2d7.0503.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 [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/61d6840b-e33a-4273-b466-58c613a98252n%40chromium.org.
