On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 1 on 2008-12-11 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In Chrome Android version 18 on 2012-06-27 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In Edge version 12 on 2015-07-29 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In Firefox version 52 on 2017-03-07 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In Firefox for Android version 52 on 2017-03-07 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In Internet Explorer version 9 on 2011-03-14
In Quest Browser version 5.0 on undefined Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In Opera version 11.6 on 2011-12-06
In Opera Android version 12.1 on 2012-10-09
In Safari version 5 on 2010-06-07
In Safari on iOS version 4.2 on 2010-11-22
In Samsung Internet version 1.0 on 2013-04-27 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In WebView Android version 4.4 on 2013-12-09 Note: The onfocusin event handler property is not supported. To listen to this event, use element.addEventListener('focusin', function() {});.
In WebView on iOS version 4.2 on 2010-11-22