What are caches?
Your system and applications generate cache files to load and work faster. Once these files became outdated, they pile up on your Mac and decrease its performance. When you delete system and user caches from Mac OS X, your Mac generates fresh caches that help your apps operate faster and increase overall system performance.
How to clear caches on a Mac manually?
Open a finder window and select “Go to Folder” in the Go menu.
Type in ~/Library/Caches and hit Enter to proceed to this folder.
This is optional, but you can highlight & copy everything to a different folder in case something goes wrong.
Highlight everything and press Command and Backspace.
Do the same with /Library/Caches (note the lack of “~”, which acted as a shortcut to your home folder in step 2).
Restart your machine so that your apps and system can generate new and fresh caches.
But is it safe to delete cache folders in OS X? Yes, every app is able to recreate fresh caches by default. Note: We recommend that you remove the insides of these folders, but not the folders themselves.
Also, if you clear cache files to free up additional space, you will need to empty your Trash. To do that, command-click on Trash and select Empty Trash.
Now to clear caches on a Mac with CleanMyMac 2
Instead of dealing with Finder and files, you can clear caches on a Mac using the new CleanMyMac 2. With it’s advanced algorithms removing system and user cache files is the simplest yet safest operation you can imagine:
First, hit Scan after the launch.
Then click Clean to perform automatic system cleanup. That operation will clean your Mac from needless system junk, including system and user caches.
Alternatively, after the scan is over you can proceed to the System Cleanup module and click Detailed Results. There you can uncheck all found categories except caches to clean them exclusively on cleanup.