On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 46 on 2015-10-13
In Chrome Android version 46 on 2015-10-14
In Edge version 79 on 2020-01-15
In Firefox version 94 on 2021-11-02 Note: Firefox implements the definitions given in CSS3 Basic Box. This defines available and not fit-available. Also, the definition of fit-content is simpler than in CSS3 Sizing.
In Firefox for Android version 94 on 2021-11-02 Note: Firefox for Android implements the definitions given in CSS3 Basic Box. This defines available and not fit-available. Also, the definition of fit-content is simpler than in CSS3 Sizing.
Not in Internet Explorer
In Quest Browser version 5.0 on undefined
In Opera version 44 on 2017-03-21
In Opera Android version 43 on 2017-09-27
In Safari version 11 on 2017-09-19
In Safari on iOS version 11 on 2017-09-19
In Samsung Internet version 5.0 on 2016-12-15
In WebView Android version 46 on 2015-10-14
In WebView on iOS version 11 on 2017-09-19