Same-site cross-origin prerendering triggered by the speculation rules API

Category: Performance
Type: New or changed feature
Status: Enabled by default (Chrome 109)
Intent stage: Shipped

Summary

Previously [1] we launched same-origin prerendering triggered by the speculation rules API. This expands coverage to also allow triggering same-site cross-origin pages [2]. This prerendering will be done with credentials and storage access, but such prerender targets will need to opt in by using the `Supports-Loading-Mode: credentialed-prerender` header. [1]: https://chromestatus.com/feature/5355965538893824 [2]: https://web.dev/same-site-same-origin/

Motivation

Prerendering is a useful technology for speeding up page loads, and ideally referrer pages would be able to prerender all target pages. By expanding the circle of prerenderable pages to include same-site cross-origin pages, we allow more navigations on the web to be instant.

Standards & signals

Specification: https://wicg.github.io/nav-speculation/prerendering.html#navigate-fetch-patch
Firefox: Closed Without a Position — No signal on previous requests for prerendering and prefetching. I added a comment to the existing issue about prerendering.
Safari: No signal — No signal on previous requests for prerendering and prefetching. I took this opportunity to re-file on their new GitHub repository in the hopes of getting some feedback.
Web developers: Positive — We've heard from a few partners that they want to prerender among other same-site origins they own, but cannot yet do so.
Tracking bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1356449

Docs: https://docs.google.com/document/d/1WsDYA8NMCSwsK8dXCKdajdAd3ZcQUu9w1eoe0hEB_nU/edit?usp=sharing

Explainers: https://github.com/WICG/nav-speculation/blob/main/prerendering-same-site.md#more-details-on-cross-origin-same-site https://github.com/WICG/nav-speculation/blob/main/opt-in.md

View on chromestatus.com