Does the website use Ctrl+f for its own Find feature, or you want to use Ctrl+f for Firefox's built-in "find in page" feature instead of Command+f? Firefox doesn't have a built-in feature to disable or reassign keyboard shortcuts. However, scripts in web pages can intercept many of them, which is how extensions like the following can reassign keys. You could take a look at whether either of them works with this one: * https://addons.mozilla.org/firefox/addon/shortkeys/ * https://addons.mozilla.org/firefox/addon/saka-key/ ''Because they need to add code to the page to intercept keys, they unfortunately require the highest level of permission to access all data. So shop carefully.''