Fancy Tab Group Manager by link1183

Tab Group Manager is a Firefox extension that helps you organize, save, and efficiently switch between groups of tabs. It allows you to:

Save your current tabs as named groups for later use
Switch between tab groups with a single click
Choose between closing unused tabs or hiding them when switching groups
Auto-group tabs by domain or custom URL patterns
Import and export your tab groups for backup or sharing
Drag and drop tabs between groups for easy organization
Access your groups via keyboard shortcuts or quick-switch panel

The extension respects pinned tabs and offers extensive customization through its options page. It's ideal for users who work with multiple projects or contexts and need to quickly switch between different sets of tabs while maintaining their workflow.