There are reasons to clear your browser's cookies too, but we're going to focus on the cache here. This is how to do the job no matter what browser you're using.

You should clear your Mac computer's cache periodically to help your device's applications run more efficiently. Here's how to do it.

To clear cache accumulated from applications on Mac, navigate to Finder, hold the Shift, Command and G buttons simultaneously, insert ~/Library/Caches in the tab provided to view your cache files ...