CSSKeyframesRule: deleteRule() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since August 2016.

The deleteRule() method of the CSSKeyframeRule interface deletes the CSSKeyFrameRule that matches the specified keyframe selector.

Syntax

deleteRule(select)

Parameters

select

A string which contains the keyframe selector of the rule to be deleted, which must be:

a comma-separated list of percentage values between 0% and 100%;
or, the keywords from or to

Note that the number and order of the values in the specified keyframe selector must match those of the targeted keyframe rule(s). White-space is disregarded.

The CSS includes a keyframes at-rule. This will be the first CSSRule returned by document.styleSheets[0].cssRules. myRules[0] returns a CSSKeyframesRule object. Returning the cssRules property would return a CSSRuleList containing two rules.

After deleting a rule with deleteRule() the cssRules property returns a CSSRuleList containing one rule.

css
@keyframes slide-in {
  from {
    transform: translateX(0%);
  }

  to {
    transform: translateX(100%);
  }
}

js
let myRules = document.styleSheets[0].cssRules;
let keyframes = myRules[0]; // a CSSKeyframesRule
keyframes.deleteRule("to");
console.log(keyframes.cssRules); // a CSSRuleList object with one rule