Name: LoAF script invokers on React sites (October 2026) - The State of Web Vitals
Creator: Arjen Karel

59.8% of React sites use DOM event listeners Long Animation Frame (LoAF) script invoker type, and 99% of those sites have a good INP, against 99% of all React sites.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 5,840 sites with Long Animation Frame (LoAF) script invoker typeBy Arjen Karel · corewebvitals.io/state-of-cwv

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INP pass rate

Sites with DOM event listeners Long Animation Frame (LoAF) script invoker type have a good INP most often: 99%, against 99% of all React sites. Sites with classic script evaluation LoAF invokers have it least often, at 98%.

SitesGood, needs improvement, poor INPMedian

All React sites1,97999%48ms

Promise microtask resolution (then / async-await) 0.8%18100%64ms

ES module <script type="module"> evaluation 0.3%9100%61ms

DOM event listener (click / scroll / input) 59.8%62499%47ms

Timer / rAF callback (setTimeout / requestAnimationFrame) 18.8%31999%53ms

Classic <script> evaluation 44.3%54198%50ms

GoodNeeds improvementPoorSites: with Chrome field data

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 5,840 sites with Long Animation Frame (LoAF) script invoker typeBy Arjen Karel · corewebvitals.io/state-of-cwv

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Long Animation Frame (LoAF) script invoker type usage

DOM event listeners is the most used: 59.8% of React sites.

Sites using each option (sites can use more than one) 5,840 sites

DOM event listener (click / scroll / input) 59.8% Classic <script> evaluation 44.3% Timer / rAF callback (setTimeout / requestAnimationFrame) 18.8%

DOM event listener (click / scroll / input) 59.8% Classic <script> evaluation 44.3% Timer / rAF callback (setTimeout / requestAnimationFrame) 18.8% Promise microtask resolution (then / async-await) 0.8% ES module <script type="module"> evaluation 0.3%

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 5,840 sites with Long Animation Frame (LoAF) script invoker typeBy Arjen Karel · corewebvitals.io/state-of-cwv

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Long Animation Frame (LoAF) script invoker type per platform

Wix sets the Long Animation Frame (LoAF) script invoker type to DOM event listeners on 74% of its sites, and 100% of Wix sites have a good INP, against 99% of all sites.

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%99%

Wix 3,502 sitesDOM event listener (click / scroll / input) 74%Classic <script> evaluation 46%100%

WordPress 1,383 sitesTimer / rAF callback (setTimeout / requestAnimationFrame) 43%Classic <script> evaluation 38%DOM event listener (click / scroll / input) 35%100%

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

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 5,840 sites with Long Animation Frame (LoAF) script invoker typeBy Arjen Karel · corewebvitals.io/state-of-cwv

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LoAF script invoker or the platform

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

On Wix, 100% of sites with DOM event listeners Long Animation Frame (LoAF) script invoker type have a good INP, against 99% of Wix sites with classic script evaluation. Within Wix, sites with DOM event listeners and classic script evaluation have a good INP about equally often. On WordPress, 100% of sites with DOM event listeners Long Animation Frame (LoAF) script invoker type have a good INP, against 99% of WordPress sites with classic script evaluation. Within WordPress, sites with DOM event listeners and classic script evaluation 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 (99% good INP, 47ms median). Classic script evaluation accounts for 44.3% (98% good INP) and timer/rAF user-callbacks account for 18.8% (99% good INP), while heavy module-script evaluation (0.3%) and unbatched Promise microtasks (0.8%) drop to 100% and 100% good INP.

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 5,840 sites with Long Animation Frame (LoAF) script invoker typeBy Arjen Karel · corewebvitals.io/state-of-cwv

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Understanding Long Animation Frame script invokers

Update visual UI state first inside click/keydown event listeners, then yield via scheduler.yield() before running analytics, storage writes, or non-critical Promise chains. Across all sites with Long Animation Frames, 59.8% trigger long frames in event listeners (99% good INP) and 0.8% in Promise microtasks (100% good INP).

Go fix it The Long Animation Frames API → Yield to the main thread → The dataLayer INP yield pattern →

The State of Web Vitals · October 2026 · React: 9,570 crawled sites · 1,979 with desktop field data · 5,840 sites with Long Animation Frame (LoAF) script invoker typeBy Arjen Karel · corewebvitals.io/state-of-cwv