On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 29 on 2013-08-20
In Chrome Android version 29 on 2013-08-21
In Edge version 12 on 2015-07-29
In Firefox version 22 on 2013-06-25 Note: Since Firefox 28, multi-line flexbox is supported.
In Firefox for Android version 22 on 2013-06-25 Note: Since Firefox for Android 28, multi-line flexbox is supported.
In Internet Explorer version 11 on 2013-10-17
In Quest Browser version 5.0 on undefined
In Opera version 12.1 on 2012-11-20
In Opera Android version 12.1 on 2012-10-09
In Safari version 9 on 2015-09-30
In Safari on iOS version 9 on 2015-09-16
In Samsung Internet version 2.0 on 2014-10-17
In WebView Android version 4.4 on 2013-12-09
In WebView on iOS version 9 on 2015-09-16