LoAF script invokers on React sites

Sites with timer and rAF callbacks Long Animation Frame (LoAF) script invoker type have a good INP most often: 96%, against 95% of all React sites. Sites with classic script evaluation LoAF invokers have it least often, at 94%.

DOM event listeners is the most used: 59.8% of React sites. Timer and rAF callbacks is 18.8% of React sites.

On Wix, 74% of sites use DOM event listeners Long Animation Frame (LoAF) script invoker type, and 97% of Wix sites have a good INP, against 95% of all sites. On WordPress, 43% of sites use timer and rAF callbacks, and 98% of WordPress sites have a good INP.

PlatformLong Animation Frame (LoAF) script invoker type on its sitesGood INP

React sites with Long Animation Frame (LoAF) script invoker type 5,840 sitesDOM event listener (click / scroll / input) 60%Classic <script> evaluation 44%Timer / rAF callback (setTimeout / requestAnimationFrame) 19%95%

WordPress 1,383 sitesTimer / rAF callback (setTimeout / requestAnimationFrame) 43%Classic <script> evaluation 38%DOM event listener (click / scroll / input) 35%98%

Wix 3,502 sitesDOM event listener (click / scroll / input) 74%Classic <script> evaluation 46%97%

DOM event listener (click / scroll / input) Classic <script> evaluation Timer / rAF callback (setTimeout / requestAnimationFrame) Promise microtask resolution (then / async-await) ES module <script type="module"> evaluation

Does the platform explain the Long Animation Frame (LoAF) script invoker type difference?

On Wix, 96% of sites with timer and rAF callbacks Long Animation Frame (LoAF) script invoker type have a good INP, against 98% of Wix sites with DOM event listeners. Within Wix, sites with timer and rAF callbacks and DOM event listeners have a good INP about equally often. On WordPress, 98% of sites with timer and rAF callbacks Long Animation Frame (LoAF) script invoker type have a good INP, against 98% of WordPress sites with DOM event listeners. Within WordPress, sites with timer and rAF callbacks and DOM event listeners have a good INP about equally often.

What triggers main-thread Long Animation Frames during load and interaction

The Long Animation Frames API (LoAF) attributes every frame over 50ms to the exact invoker that started the script task. Across 3,490 sites (59.8% of LoAF sites), DOM event listeners trigger long frames (95% good INP, 79ms median). Classic script evaluation accounts for 44.3% (94% good INP) and timer/rAF user-callbacks account for 18.8% (96% good INP), while heavy module-script evaluation (0.3%) and unbatched Promise microtasks (0.8%) drop to 94% and 88% good INP.