Web platform features explorer

em unit

Widely available since 2018-01-29
Tags: css Groups: CSS > Units

The em CSS length unit is a font-relative length equal to the specified font size. In an element with a 2 inch font, 1em equals 2 inches.

Browser support

  • Chrome 1 Released on 2008-12-11
  • Chrome Android 18 Released on 2012-06-27
  • Edge 12 Released on 2015-07-29
  • Firefox 1 Released on 2004-11-09
  • Firefox for Android 4 Released on 2011-03-29
  • Safari 1 Released on 2003-06-23
  • Safari on iOS 1 Released on 2007-06-29