Element: computedStyleMap() method

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.





Return value


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.

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

We add a little bit of 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().

// 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 thru 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");

  // values
  const cssValue = document.createElement("dd");

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 'a' to the 'p', and you'll notice a difference in the margin-top and margin-bottom default computed values.


CSS Typed OM Level 1
# dom-element-computedstylemap

Browser compatibility

BCD tables only load in the browser