Long Animation Frames API

A Chrome browser API that identifies which specific scripts cause slow interactions by providing frame-level attribution data.

The Long Animation Frames API (LoAF), available since Chrome 123, extends the older Long Tasks API by providing script-level attribution for slow frames. When an interaction exceeds expected duration, LoAF identifies the specific script (including third-party scripts) responsible for blocking the main thread. This granularity enables developers to pinpoint whether analytics tools, consent managers, or other third-party code is causing INP failures.

Also known as

LoAF, LoAF API, Long Animation Frames, long animation frames API