On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 1 on 2008-12-11
In Chrome Android version 18 on 2012-06-27
In Edge version 12 on 2015-07-29
In Firefox version 3.5 on 2009-06-30
In Firefox for Android version 4 on 2011-03-29
In Internet Explorer version ≤11 on undefined
In Quest Browser version 5.0 on undefined
In Opera version 15 on 2013-07-02
In Opera Android version 14 on 2013-05-21
In Safari version 3 on 2007-10-26 Note: Before Safari 12.1, overlay only had an effect on legacy scrollbars on macOS. Since Safari 12.1, it is parsed as auto.
In Safari on iOS version 2 on 2008-07-11 Note: Before Safari on iOS 12.1, overlay only had an effect on legacy scrollbars on macOS. Since Safari on iOS 12.1, it is parsed as auto.
In Samsung Internet version 1.0 on 2013-04-27
In WebView Android version 4.4 on 2013-12-09
In WebView on iOS version 2 on 2008-07-11 Note: Before WebView on iOS 12.1, overlay only had an effect on legacy scrollbars on macOS. Since WebView on iOS 12.1, it is parsed as auto.