coderef

Heading offsetLimited availability

The headingoffset HTML attribute offsets the heading level of descendant <h1>–<h6> elements. The headingreset HTML attribute prevents heading offset computation from traversing beyond the element.

Not yet supported in all major browsers — check the table and provide a fallback.

How to use ↓Compare browsers

Browser support

DesktopChrome
✕Not supportedup to 155
Current: 155
Edge
✕Not supportedup to 154
Current: 154
Firefox
✕Not supportedup to 157
Current: 157
Safari
✕Not supportedup to 27
Current: 27
MobileChrome Android
✕Not supportedup to 155
Current: 155
Firefox Android
✕Not supportedup to 157
Current: 157
Safari iOS
✕Not supportedup to 27
Current: 27

How to use

Not supported in Chrome, Edge, Firefox, Safari, Chrome Android, Firefox Android, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.

Example

Full syntax and examples are on MDN: headingoffset.

Feature detection

JS · check before using
if ("HTMLElement" in globalThis && "headingOffset" in HTMLElement.prototype) {
  // HTMLElement.headingOffset is available
}

Documentation (MDN)

Specification

Sub-features

Support for each part of the feature (4). The overall table above shows when the whole feature works.

Sub-featureChromeEdgeFirefoxSafariChrome AndroidFirefox AndroidSafari iOS
HTMLElement.headingOffset✕✕✕✕✕✕✕
HTMLElement.headingReset✕✕✕✕✕✕✕
headingoffset✕✕✕✕✕✕✕
headingreset✕✕✕✕✕✕✕