Animation.persist()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The persist() method of the Web Animations API's Animation interface explicitly persists an animation, when it would otherwise be removed due to the browser's Automatically removing filling animations behavior.

Syntax

animation.persist(); 

Parameters

None.

Return value

None.

Examples

In our simple replace indefinite animations demo, you can see the following code:

const divElem = document.querySelector('div');

document.body.addEventListener('mousemove', evt => {
  let anim = divElem.animate(
    { transform: `translate(${ evt.clientX}px, ${evt.clientY}px)` },
    { duration: 500, fill: 'forwards' }
  );

  anim.commitStyles();

  //anim.persist()

  anim.onremove = function() {
    console.log('Animation removed');
  }

  console.log(anim.replaceState);
});

Here we have a <div> element, and an event listener that fires the event handler code whenever the mouse moves. The event handler sets up an animation that animates the <div> element to the position of the mouse pointer. This could result in a huge animations list, which could create a memory leak. For this reason, modern browsers automatically remove overriding forward filling animations.

You can see the replaceState of the animation being logged at the end of the handler. This will be active for each animation by default, or persisted if the persist() call is uncommented.

Specifications

Specification Status Comment
Web Animations
The definition of 'persist()' in that specification.
Working Draft

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
persist
Experimental
Chrome No support No
Notes
No support No
Notes
Notes Currently Chrome Canary only
Edge No support NoFirefox Full support 75IE No support NoOpera No support NoSafari Full support 13.1WebView Android No support NoChrome Android No support No
Notes
No support No
Notes
Notes Currently Chrome Canary only
Firefox Android No support NoOpera Android No support NoSafari iOS Full support 13.4Samsung Internet Android No support No

Legend

Full support  
Full support
No support  
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
See implementation notes.
See implementation notes.

See also