CSSStyleSheet: replace() method

Baseline 2023

Newly available

Since March 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The replace() method of the CSSStyleSheet interface asynchronously replaces the content of the stylesheet with the content passed into it. The method returns a promise that resolves with the CSSStyleSheet object.

The replace() and CSSStyleSheet.replaceSync() methods can only be used on a stylesheet created with the CSSStyleSheet() constructor.





A string containing the style rules to replace the content of the stylesheet. If the string does not contain a parseable list of rules, then the value will be set to an empty string.

Note: If any of the rules passed in text are an external stylesheet imported with the @import rule, those rules will be removed, and a warning printed to the console.

Return value

A Promise that resolves with the CSSStyleSheet.


NotAllowedError DOMException

Thrown if one of these two conditions is met:

  • The stylesheet was not created using the CSSStyleSheet() constructor.
  • The stylesheet is flagged as unmodifiable.


In the following example a new stylesheet is created and two CSS rules are added using replace(). The first rule is then printed to the console, which will return: body { font-size: 1.4em; }

const stylesheet = new CSSStyleSheet();

  .replace("body { font-size: 1.4em; } p { color: red; }")
  .then(() => {
  .catch((err) => {
    console.error("Failed to replace styles:", err);


CSS Object Model (CSSOM)
# dom-cssstylesheet-replace

Browser compatibility

BCD tables only load in the browser

See also