how often should I delete cache on Safari

I only clear cache when I am having problems. If i have no problems, I see no reason to clear cache.

Cache is there to improve performance. It is only when it becomes corrupt that it needs to be cleared.

Allan

Whenever you want to. There's no real need to delete it very often at all, but you can't hurt anything except your page-loading speed by clearing the cache frequently if that's what you're comfortable doing. I clear mine every few days.