When you use the internet, your computer stores information from frequently visited locations that allow your computer to save time loading pages in a file called a cache. You can clear this information for privacy reasons, or free up short-term storage space on your computer. If you need to clear your cache on Safari, please follow these steps:
iOS:
Delete your Safari history, cache, and cookies on iPhone - Apple Support
MacOS:
Clear your cache and cookies in Safari on Mac - Apple Support