Quick Commands is a Firefox extension that works like Vivaldi's shortcuts
Vivaldi users may be familiar with a feature called Quick Commands. These are keyboard shortcuts which allow you to do various things quickly like switching tabs, finding a specific tab, do an online search, and more.
If you want a similar set of controls in Firefox, you can get it with the help of the Quick Commands extension. The name alone should tell you that the add-on is inspired by Vivaldi's built-in option.
Here's how to use it. Install the add-on and press the hotkey Alt + Shift + R to bring up the Quick Commands window. Or, you can click on the button that the add-on places on Firefox's toolbar.
Quick Commands' interface will pop-up, it lists all your tabs. Start typing a keyword and the extension will filter the list to display the relevant results. Use the up and down arrow keys to navigate the list, when a tab is highlighted hit the enter key to switch to the tab. Or if you prefer the mouse, click on a result to go to the corresponding tab. The list includes tabs from all windows.
The first item that Quick Commands displays isn't really a search result, rather this is a shortcut that you can use to perform a Google search based the keyword that you entered. Granted you can do this from the browser's awesome bar, but by using the add-on you can check if you've already looked up the content, and if a tab related to the search term is open.
The extension is not limited to tabs, it also searches your browsing history and bookmarks to help you find the tab that you're looking for.
You can tell whether an item in the list is an open tab, or not by looking at the right-hand side of the modal interface. Quick Commands lists items by sections such as tabs, history, bookmarks. The number next to each section represents the number of items in the list, e.g. total number of tabs, bookmarks, etc.
The add-on has two additional useful options which are listed under the "commands" section. The first of these is Mute All Tabs, while the other one is Unmute All Tabs. To access them quickly, use the hotkey and type mute and select the option.
Despite the "All" in the name, the command only mutes tabs which play some video or audio, the other tabs remain unaffected. This also means that the mute commands do not work when no active media tab is found. If you've some media playing in a tab and want to quickly turn it off, you will find these options very useful.
You can dismiss the Quick Commands' window by hitting the Escape key. Go to the add-on's options page to set the number of results that should appear. Not a fan of the theme? Switch to the dark theme. Quick Commands has a custom theme which lets you choose the color of the background, search window's background, text, highlighted item's background, links, and selected text.
Download Quick Commands for Firefox. The extension is open source. There is no option to change the hotkey.