How to clear cache on a Mac computer to make it run more efficiently
1. Press shift-command-G with your Finder window open.
2. Enter the following command into the search box: ~/Library/Caches.
3. Click “Go.” This will bring you to the folder that contains all of your Mac’s cached files.
4. Press command-A to select all folders.
5. Click command-delete.
6. You’ll get a pop-up asking to confirm that you want to delete all of those files, and you’ll need to enter your Mac’s password to complete the action.
Source: How to clear cache on a Mac computer to make it run more efficiently – INSIDER