:defaultBaseline · Widely available
The :default CSS pseudo-class matches the default element in a group of related form controls, such as checkboxes and radio buttons with the checked attribute.
Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Jan 15, 2020. Widely available since Jul 15, 2022.
Browser support
DesktopChrome
1–9Not supported
10+Supportedsince Mar 8, 2011
Current: 155Edge
12–18Not supported
79+Supportedsince Jan 15, 2020
Current: 154Firefox
1–3.6Not supported
4+Supportedsince Mar 22, 2011
Current: 157Safari
1–4Not supported
5+Supportedsince Jun 7, 2010
Current: 27MobileChrome Android
18+Supportedsince Jun 27, 2012
Current: 155Firefox Android
4+Supportedsince Mar 29, 2011
Current: 157Safari iOS
1–4.2Not supported
5+Supportedsince Oct 12, 2011
Current: 27How to use
This feature is Baseline widely available — use it freely, no fallback needed.
Example
Full syntax and examples are on MDN: :default.
Feature detection
CSS · check before using
@supports selector(:default) {
/* styles that use :default */
}
/* or in JavaScript */
if (CSS.supports("selector(:default)")) {
// use it
}