The Alt, Ctrl, and Shift keys have a dedicated function when used in your browser. In fact, their behavior is pretty standard throughout browsers but if you need to change how these keys work, more specifically, how they work when you click on a link while holding one of them down, give Click Modifiers a try. It’s a Firefox add-on the lets you change the behavior of the three modifier keys when used with the left-click button on your mouse/trackpad. Changing the behavior is made simple by letting the user pick from a drop-down list the behavior they want to set for a particular key. Before you head into the details, you should know that the add-on will only change the behavior for actions like Ctrl+Left-Click and not for any action that doesn’t involve the mouse, for example, Ctrl+F will still open the find bar.
Click Modifiers is a no-restart add-on so just install it and head over to its options. Be default, the add-on will not modify any of the keys. The first three options let you modify the Alt, Ctrl, and Shift keys respectively. The modified options available for each modifier button are the same; Open link in current window/tab, Open link in new window, open link in new tab, open link in new background tab, and save link. Besides the three modifier keys, the add-on will let you assign one of these behaviors to the middle-click button from a similar drop-down in the settings.
If you ever want to reset one of the keys, you can select the ‘Use default action’ option. The add-on comes with its limitations; on OS X the action associated with Control click can’t be modified. The add-on is very obviously basic in functionality but it does what it says on the label so nothing to complain about though plenty left to want for.
Where the add-on aims to make it simple to change modifier key behavior, it can add additional features while still keeping the add-on simple such as the ability to disable the use of a modifier key in the browser or on specific websites. This could be immensely useful for users who use powerful web apps but aren’t fans of the hotkeys they support. For example, I would personally like to kill the ability to publish in WordPress using the Ctrl+Alt+p and others might want to prevent the browser from executing similar actions in other web apps. Overall, Click Modifiers is simple in concept and function but has the potential to become a tool for power users with the addition of more features.