attr() (content only)
Widely available since 2018-01-29
The attr() CSS function, in content property declarations, sets a ::before or ::after pseudo-element's content to the value of the specified HTML attribute.
Learning resources on MDN
Browser support
- Chrome 2 Released on 2009-05-21
- 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 3.1 Released on 2008-03-18
- Safari on iOS 2 Released on 2008-07-11