Firefox creators made things really user friendly IMO
You can clear Firefox cache by following these three steps:
- Press Ctrl+Shift+Del
- Choose the time range and tick the part of your history you wanna get rid of (Browsing and Download History, Forms & Search Data, etc…), you may need to click the arrow to show those details
- Click “Clear Now”
After doing your first experiment, you will see that it takes only a few seconds to clear firefox cache.