Quick Unload Tab by ssmg

Press Cmd+Shift+U (macOS) or Ctrl+Shift+U (Windows/Linux) to unload the tab you're on. Firefox frees its memory and CPU, and you're taken to the next loaded tab, skipping ones that are already unloaded.

The unloaded tab stays in the tab bar and reloads when you click it again. It's the same as the built-in "Unload Tab" item in the tab context menu, just on a key.

Change the shortcut: about:addons → gear icon → Manage Extension Shortcuts.

Using tab groups? Right-click any tab in a group → "Unload Tabs in Group" to unload the whole group at once and collapse it. You can turn off collapsing in the add-on's preferences.

Permissions: "menus" and "tabGroups" for that tab menu item, "storage" to remember your setting. No data collection. Source code: https://github.com/semihsmg/quick-unload-tab