LCP updates in Chrome 116

[Ian Clelland]

Starting in August 2023, just after the release of Chrome 116, Chrome has begun to take into account the first displayed frame of animated images or autoplaying videos for LCP calculations.

This is likely to affect the LCP of animation- or video-heavy pages.

Videos without poster images were previously not included in LCP calculations at all, but will now be considered eligible LCP candidates when the first frame is rendered. (This will generally only apply to large muted autoplaying videos only, as videos with sound require a user interaction to begin playing, and LCP is only counted up until the first interaction on the page)

Animated bitmap images will also use the timing of their first rendered frame, rather than waiting until the data has been completely downloaded. For pages where an animated image is the largest painted element, this should generally result in an improvement to LCP scores.

For more details, see the changelog.