z-indexBaseline · Widely available
The z-index CSS property orders overlapping elements, with higher values appearing in front of or on top of lower values.
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
1–2Not supported
3+Supportedsince Jun 17, 2008
Current: 157Safari
1+Supportedsince Jun 23, 2003
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: z-index.
Feature detection
CSS · check before using
@supports (z-index: initial) {
/* styles that rely on z-index */
}
/* or in JavaScript */
if (CSS.supports("z-index", "initial")) {
// use it
}Specification
Sub-features
Support for each part of the feature (4). The overall table above shows when the whole feature works.