Firefox has option that lets you close all tabs but the active one. The problem is, what if you need to keep open some other inactive tabs as well? Let’s say that you want to keep 5 tabs open and close the rest. Closing the not-anymore-needed tabs one by one is sure a waste of time if you have plenty of them. This is where Tab Mix Plus comes very handy.
The add-on has a tab protection functionality. When activated on a tab, it protects the tab from being accidentally closed. When a tab is being protected, its close button is missing and will be restored once you remove the protection. Not only the close button, the shortcut key “Ctrl + W” is also deactivated.
Install Tab Mix Plus (v0.4.0.4), restart Firefox, right-click on each tab that you want to keep open, and select “Protect Tab”. After protecting the tabs, right-click again on any of them and select “Close Other Tabs”. The other tabs will be closed, leaving only the active tab and the protected ones.
Tab Mix Plus also has an option to lock tab. What the difference does it have between the lock and protect tab functionalities? While the protection feature prevent the tab from being closed, the lock protects the web page from being replaced with others. Any link that you click within that page will be opened in a new tab. In other words, you can close the locked tab but cannot navigate to other links within the tab, and the protected tab works vice versa.
A tab can also be locked as well as protected at the same time. When you do this, the tab cannot be closed and you cannot open other links within.