Element: computedStyleMap() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

The computedStyleMap() method of the Element interface returns a StylePropertyMapReadOnly interface which provides a read-only representation of a CSS declaration block that is an alternative to CSSStyleDeclaration.

Syntax

js
computedStyleMap()

Parameters

None.

Return value

Examples

We start with some simple HTML: a paragraph with a link, and a definition list to which we will add all the CSS Property / Value pairs.

html
<p>
  <a href="https://example.com">Link</a>
</p>
<dl id="regurgitation"></dl>

We add a little bit of CSS

css
a {
  --color: red;
  color: var(--color);
}

We add JavaScript to grab our link and return back a definition list of all the CSS property values using computedStyleMap().

js
// get the element
const myElement = document.querySelector("a");

// get the <dl> we'll be populating
const stylesList = document.querySelector("#regurgitation");

// Retrieve all computed styles with computedStyleMap()
const allComputedStyles = myElement.computedStyleMap();

// iterate through the map of all the properties and values, adding a <dt> and <dd> for each
for (const [prop, val] of allComputedStyles) {
  // properties
  const cssProperty = document.createElement("dt");
  cssProperty.appendChild(document.createTextNode(prop));
  stylesList.appendChild(cssProperty);

  // values
  const cssValue = document.createElement("dd");
  cssValue.appendChild(document.createTextNode(val));
  stylesList.appendChild(cssValue);
}

In browsers that support computedStyleMap(), you'll see a list of all the CSS properties and values. In other browsers you'll just see a link.

Did you realize how many default CSS properties a link had? Update the document.querySelector("a") to document.querySelector("p"), and you'll notice a difference in the margin-top and margin-bottom default computed values.

Specifications

Specification
CSS Typed OM Level 1
# dom-element-computedstylemap

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
computedStyleMap

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
See implementation notes.