I’m a big fan of both Firefox and Opera, but it’s fair to say that Firefox is the more customisable of the two. The wealth of freely available add-ons is staggering, easily blowing Opera’s Widgets out of the water.
Nevertheless, Opera has a bunch of great features that Firefox does not. The following is a list of add-ons and semi-hidden features that can be used to replicate Opera’s best bits in Firefox.
In Opera: Stores personal details (email, etc.) and passwords, allowing them to be entered into web forms automatically.
In Firefox: While not a perfect match, the Secure Login add-on replicates the wands auto login/password memory feature. A keyboard shortcut can be specified (Interface > Keyboard Shortcut) to match Opera’s Ctrl + Enter (or anything else), but the super-handy mouse click shortcut cannot be replicated, unfortunately.
In Opera: Displays nine bookmarks as thumbnail images when new tabs/windows are opened.
In Firefox: The Speed Dial add-on not only provides the same functionality as its Opera counterpart, but also offers a host of additional customisation options, including: number of thumbnails, thumbnail size, automatic refreshing, keyboard controls, and more.
In Opera: Holding Ctrl + Shift and left clicking opened a link in a new background tab.
In Firefox: Simply holding Ctrl while left clicking achieves the same thing, while Ctrl + Shift and left clicking opens a foreground tab. Middle clicking (scroll wheel) on a link opens a background tab in both browsers. A full list of mouse shortcuts can be found here, if you’re interested.
Undo Closed Tab
In Opera: Ctrl + Z miraculously revives the most recently closed tab (repeatable ad nauseum).
In Firefox: Ctrl + Shift + T offers the same functionality be default, but the Undo Closed Tabs Button add-on is a far more comprehensive tool. It allows you to sift through a list of recently closed tabs, choosing which you wish to restore. It’s all hidden behind a dinky little button on the toolbar, too.
Custom Keyboard Shortcuts
In Opera: Tools > Preferences > Advanced > Shortcuts > Keyboard Setup > Edit offers a complete list of keyboard shortcuts, allowing you to customise each at will.
In Firefox: No such functionality exists by default in Firefox, but, as you might have guessed, there is an add-on for it. The KeyConfig add-on isn’t up to date in the Mozilla add-ons directory, but the preceding link will take you to the most recent version. Details can be found here.
Simply hit up Tools > Keyconfig and customise away! Hunt down the ‘key_undoCloseTab’ shortcut to improve upon the previous solution and change Ctrl + Shift + T to the far more intuitive Ctrl + Z (it’s already assigned to the undo action, but the two can coexist just fine).