The State of Web Vitals

Shopify main-thread task scheduling APIs and the Core Web Vitals

100.0% of audited sites (8,246) schedule tasks via setTimeout (99% good INP), 99.8% use requestAnimationFrame (99% good INP), 99.7% use requestIdleCallback (99% good INP), and 4.2% adopt modern scheduler.yield() (99% good INP, 69ms median).

Field data PhoneDesktopAll Scope All sites October 2026 edition · Desktop field outcomes · Shopify sites only
Shopify Scoped to 8,248 sites out of 203,892 analyzed (cms) Compare with all sites →

100.0% of Shopify sites use setTimeout() main-thread scheduling API usage, and 99% of those sites have a good INP, against 99% of all Shopify sites.

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
1

INP pass rate

Sites with setTimeout() main-thread scheduling API usage have a good INP most often: 99%, against 99% of all Shopify sites. Sites with scheduler.yield() task scheduling have it least often, at 99%.

SitesGood, needs improvement, poor INPMedian
All Shopify sites3,81899%61ms
setTimeout() 100.0%3,81899%61ms
requestAnimationFrame() 99.8%3,81199%61ms
requestIdleCallback() 99.7%3,80599%61ms
setInterval() 89.5%3,59099%62ms
scheduler.yield() 4.2%16899%69ms
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
2

Main-thread scheduling API usage usage

SetTimeout() is the most used: 100.0% of Shopify sites.

Sites using each option (sites can use more than one) 8,246 sites
setTimeout() 100.0% requestAnimationFrame() 99.8% requestIdleCallback() 99.7% setInterval() 89.5%
setTimeout() 100.0% requestAnimationFrame() 99.8% requestIdleCallback() 99.7% setInterval() 89.5% scheduler.yield() 4.2%
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
3

Main-thread scheduling API usage per framework

jQuery sets the main-thread scheduling API usage to setTimeout() on 100% of its sites, and 99% of jQuery sites have a good INP, against 99% of all sites. Vue sets the main-thread scheduling API usage to requestIdleCallback() on 100% of its sites, and 100% of Vue sites have a good INP.

FrameworkMain-thread scheduling API usage on its sitesGood INP
All Shopify sites 8,246 sitessetTimeout() 100%requestAnimationFrame() 100%requestIdleCallback() 100%setInterval() 89%99%
Vue 933 sitesrequestIdleCallback() 100%setTimeout() 100%requestAnimationFrame() 100%setInterval() 99%100%
jQuery 3,153 sitessetTimeout() 100%requestAnimationFrame() 100%requestIdleCallback() 99%setInterval() 95%99%
setTimeout() requestAnimationFrame() requestIdleCallback() setInterval() scheduler.yield()
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
4

Scheduling APIs or the framework

Does the framework explain the main-thread scheduling API usage difference?

On jQuery, 99% of sites with setTimeout() main-thread scheduling API usage have a good INP, against 99% of jQuery sites with requestAnimationFrame(). Within jQuery, sites with setTimeout() and requestAnimationFrame() have a good INP about equally often. On Vue, 100% of sites with setTimeout() main-thread scheduling API usage have a good INP, against 100% of Vue sites with requestAnimationFrame(). Within Vue, sites with setTimeout() and requestAnimationFrame() have a good INP about equally often.

How timer churn (setInterval) and yielding APIs affect input responsiveness

Nearly every site uses setTimeout() (100.0%, 99% good INP), while 89.5% run recurring setInterval() timers (99% good INP, 62ms median) and 99.8% use requestAnimationFrame() (99% good INP). For background work, 99.7% call requestIdleCallback() (99% good INP, 61ms median), while the 4.2% (343 sites) adopting scheduler.yield() achieve a 69ms median INP (99% good INP) by yielding to pending user input with priority continuation.

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
5

Understanding main-thread task scheduling APIs

Use scheduler.yield() (with a setTimeout(0) fallback) to break up long main-thread tasks so the browser can paint pending user interactions before resuming work, and eliminate high-frequency setInterval() polling. Across all audited sites, 4.2% use scheduler.yield() (69ms median INP) while 99.7% use requestIdleCallback() (61ms median INP).

Go fix it Yield to the main thread → The dataLayer INP yield pattern → JavaScript priority levels →
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals Interaction invoker types → CSS hints → Yielding strategy → INP phase breakdown → By Arjen Karel · 8,246 crawled Shopify sites (3,818 with desktop Chrome field data, October 2026) · How we measured