How to reset Safari

Safari/Preferences/Advanced - enable the Develop menu, then go there and Empty Caches. Quit/reopen Safari and test. Then try Safari/History/Show History and delete all history items. Quit/reopen Safari and test. You can also try try Safari/Clear History…. The down side is it clears all cookies. Doing this may cause some sites to no longer recognize your computer as one that has visited the web site. Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J. When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder. Select Library/Caches/com.apple.Safari/Cache.db and move it to the trash.

Go to Safari Preferences/Extensions and turn all extensions off. Test. If okay, turn the extensions on one by one until you figure out what extension is causing the problem.

Safari Corruption See post by Linc Davis

Safari Reset

Safari - History menu - Clear History will remove history, cache, cookies etc as reset did : unless used with etc Option key, in which case it clears History but keeps website data.

>>...can I just completely dump Safari and re download a fresh version?

No. Although there are some standalone installers, for certain OS versions : they don't affect existing cache/cookies/settings