Bet you did not know this: scroll is not an excluding input for CLS. There is no 500ms grace period. Every layout shift during a scroll counts.

That hide-on-scroll header animating top? New layout shift on every frame. Every scroll direction change.

Fix: replace top with transform: translateY(). Compositor only. Zero shifts.

Lighthouse will never catch this. It does not scroll.

https://corewebvitals.io/pagespeed/scroll-triggered-animations-cause-cls

#CoreWebVitals #CLS #WebPerformance #WebDev #CSS

LCP now emits per frame based on painted content, not pending images. You'll see more intermediate candidates showing actual load progression instead of getting blocked by slow large images.

https://chromestatus.com/feature/5167930847395840

Speculation rules just got a major upgrade.

The new form_submission field lets you prerender form submissions.

Search bars, login redirects, all now prerenderable.

👇

https://chromestatus.com/feature/5074313831120896