Mac storage basics · Browsers and everyday apps
How do I see and remove the data individual websites store in Safari?
Short answer: Go to Safari → Settings → Privacy → Manage Website Data, select sites and click Remove. It signs you out of those sites and removes their offline data.
In Safari choose Safari → Settings → Privacy and click Manage Website Data…. You'll see every site that has stored data on your Mac. Select one or more and click Remove, or Remove All to clear everything.
Removing a site's data signs you out of it and deletes anything it saved for offline use, such as drafts in a web app — so remove only sites you don't rely on offline. Ordinary cache clearing is covered in clearing the Safari cache.