The autofocus attribute on a <button> tag
specifies that the button has focus once the page is loaded..
Focus means that keyboard input is directed to that control.
A <button> with autofocus enabled. The button currently has focus. Press the space bar or the enter key to trigger the button click event.
<button autofocus
onclick="alert('Yes. I have autofocus.')">Confirm</button>
The autofocus attribute sets focus to the button upon page load.
Only a single element on a page can have focus.
Therefore, only one element on a page can have the autofocus attribute.
<button autofocus>
Here is when autofocus support started for each browser:
 Chrome
|
5.0 | May 2010 |
 Firefox
|
4.0 | Mar 2011 |
 IE/Edge
|
10.0 | Sep 2012 |
 Opera
|
9.6 | Oct 2008 |
 Safari
|
5.0 | Jun 2010 |
Back to <button>
