How to close the search box in Firefox with a keyboard shortcut when this box is out of focus?

In Firefox, by Ctrl+F a small search box is opened and one can search through the page.

If this box is still under focus, by ESC on can close it. But if this box is out of focus (for example if one clicks on some place of the webpage) the shortcut ESC for closing it does not work.

How to close this search box in this situation with a keyboard shortcut (i.e. without using the mouse)?

To be precise I use Firefox 49.0.1 on Win7.

Solution 1:

Press Ctrl+F again and then ESC

Solution 2:

The easiest way is to put the find bar back in focus with Ctrl+F and then close it with Esc.

The add-on FindBar Tweak offers an option to close the find bar with Ctrl+F when it is unfocussed.