Firefox - Get "Highlight all" button to be on by default

Starting at Firefox 50 you can change the default value in the settings.

Type about:config in the browser's address bar and hit enter.
Confirm you will be careful if the warning prompt appears.
The parameter findbar.highlightAll determines whether highlight all is enabled or not when you search in Firefox.

Source: http://www.ghacks.net/2016/06/11/firefox-page-search-improvements/

You could try the latest version 1.3.4 of FindBar Tweak. https://addons.mozilla.org/en-US/firefox/addon/findbar-tweak/versions/

The "Highlight All" checkbox can be found in the extension's "Highlight" preferences panel.

You don't need any extension nor to go to about:config.

Since Firefox 54, just do a search (ctrl+f) and enable highlight all (alt+a). It will remember that automatically on future searches.

It is not necessary anymore to enable it through about:config

(please, upvote so more people can know it)

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