W3cubDocs

/Web APIs

CSSStyleDeclaration: length property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨July 2015⁩.

The read-only property returns an integer that represents the number of style declarations in this CSS declaration block.

Value

An integer that provides the number of styles explicitly set on the parent of the instance.

Examples

The following gets the number of explicitly set styles on the following HTML element:

<div
  id="div1"
  style="margin: 0 10px; background-color: #ccaa11; font-family: monospace"></div>

JavaScript code:

const myDiv = document.getElementById("div1");
const divStyle = myDiv.style;
const len = divStyle.length; // 6

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android WebView on iOS
length 1 12 1 ≤12.1 6 18 4 ≤12.1 6 1.0 4.4 6

© 2005–2025 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/CSSStyleDeclaration/length