How Do I Empty the Cache on a Mac OSX?
The cache folder on your Macintosh computer temporarily holds information received from previously viewed Internet sites, which allows your browser to load previously viewed sites quickly the next time you visit them. After a while of Internet browsing, your cache folder takes up large amounts of hard drive space and must be emptied to recover free space.
Empty Cache From Safari
Click the "Safari" icon on your dock, and click "Safari" at the top of the menu.
Click "Empty Cache" from the drop-down menu, and click "Empty" to confirm the action.
Click "Safari" at the top of the menu, and click "Reset Safari" from the drop-down menu as an alternative way to empty the cache. Check the box next to "Empty the cache" and click "Reset."
Empty Cache Using Firefox
Open the "Applications" folder in Finder and double-click the "Firefox" icon to run the application.
Click "Firefox" at the top of the screen and select "Preferences" from the drop-down menu.
Click the "Advanced" button and click the "Network" tab.
Click the "Clear Now" button, and click the red button in the upper-left corner to close out of the window.