<h1> through <h6>Baseline · Widely available
The <h1> through <h6> HTML elements represent six levels of section headings, in order of decreasing importance.
Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Jul 29, 2015. Widely available since Jan 29, 2018.
Browser support
DesktopChrome
1+Supportedsince Dec 11, 2008
Current: 155Edge
12+Supportedsince Jul 29, 2015
Current: 154Firefox
1+Supportedsince Nov 9, 2004
Current: 157Safari
1–2Not supported
3+Supportedsince Oct 26, 2007
Current: 27MobileChrome Android
18+Supportedsince Jun 27, 2012
Current: 155Firefox Android
4+Supportedsince Mar 29, 2011
Current: 157Safari iOS
1+Supportedsince Jun 29, 2007
Current: 27How to use
This feature is Baseline widely available — use it freely, no fallback needed.
Example
Full syntax and examples are on MDN: HTMLHeadingElement.
Feature detection
JS · check before using
if ("HTMLHeadingElement" in globalThis) {
// HTMLHeadingElement is available
} else {
// load a polyfill or use a fallback
}Documentation (MDN)
Sub-features
Support for each part of the feature (7). The overall table above shows when the whole feature works.