Load Background Tabs Lazily is a Firefox extension designed to optimize tab loading for users with slow internet connections. It mimics the functionality of the outdated Load Tabs Progressively add-on, allowing users to manage multiple background tabs efficiently. The extension limits the number of concurrently loading tabs, placing newly created tabs in a queue and only permitting a specified number to load at any given time. Once a tab finishes loading, the next one in line is allowed to begin, preventing browser and CPU overload.

This extension specifically targets background tabs with HTTP(S) URLs, automatically removing non-HTTP(S) tabs when their URLs become visible. Users can access various settings and commands through a toolbar button or the Options page. However, it is essential to grant permissions for the extension to function correctly, including access to all websites, which may pose security risks. Overall, this tool is beneficial for those who frequently open multiple tabs without overwhelming their browser.