Tab Discard (Suspender) от Glin

Tab Discard (Suspender) is an addon that lets you easily suspend all inactive tabs with just one click.

Suspending tabs can greatly reduce the memory and speeds up your browser. When you click on a suspended tab (make it active) it will be loaded with the previous content automatically.

This addon is useful when you have several open tabs, you can suspend them all (free up the memory) with just one click and then visit them one-by-one to unsuspend. This way, your browser will use the least amount of memory and have better performance.

To report bugs, please visit the addon's homepage and fill the bug report form.