react-spring's fork of rafz one frameloop to rule them all

Usage no npm install needed!

<script type="module">
  import reactSpringRafz from 'https://cdn.skypack.dev/@react-spring/rafz';



Coordinate requestAnimationFrame calls across your app and/or libraries.

  • < 700 bytes min+gzip
  • Timeout support
  • Batching support (eg: ReactDOM.unstable_batchedUpdates)
  • Uncaught errors are isolated
  • Runs continuously (to reduce frame skips)



import { raf } from '@react-spring/rafz'

// Schedule an update
raf(dt => {})

// Start an update loop
raf(dt => true)

// Cancel an update

// Schedule a mutation
raf.write(() => {})

// Before any updates
raf.onStart(() => {})

// Before any mutations
raf.onFrame(() => {})

// After any mutations
raf.onFinish(() => {})

// Set a timeout that runs on nearest frame
raf.setTimeout(() => {}, 1000)

// Use a polyfill

// Get the current time
raf.now() // => number

// Set how you want to control raf firing
raf.frameLoop = 'demand' | 'always'



  • Functions can only be scheduled once per queue per frame.
  • Thus, trying to schedule a function twice is a no-op.
  • The update phase is for updating JS state (eg: advancing an animation).
  • The write phase is for updating native state (eg: mutating the DOM).
  • Reading is allowed any time before the write phase.
  • Writing is allowed any time after the onFrame phase.
  • Timeout handlers run first on each frame.
  • Any handler (except timeouts) can return true to run again next frame.
  • The raf.cancel function only works with raf handlers.
  • Use raf.sync to disable scheduling in its callback.
  • Override raf.batchedUpdates to avoid excessive re-rendering in React.



Wrap a function to limit its execution to once per frame. If called more than once in a single frame, the last arguments are used.

let log = raf.throttle(console.log)

log(2) // nothing logged yet

raf.onStart(() => {
  // "2" is logged by now

// Cancel a pending call.

// Access the wrapped function.

Prior art