Safari unstable

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

If that doesn't work, try running this program in your normal account , then copy and paste the output in a reply. The program was created by etresoft, a frequent contributor. Please use copy and paste as screen shots can be hard to read. On the screen with Options, please open Options and check the bottom 2 boxes before running. Click “Share Report” button in the toolbar, select “Copy Report” and then paste into a reply. This will show what is running on your computer. No personal information is shown.

Etrecheck – System Information

Go to Safari (top menu), scroll down to reset and clear caches. Then test.

Read this article Non-responsive DNS server or invalid DNS configuration can cause long delay before webpages load - Apple Support

Enter in user library macOS Sierra: Library folder

Delete the contents of Caches , Cookies , Saved Application state , folder Safari into the trash .

Restart the computer and empty the trash .

Note : In very nearest condition Safari folder can be deleted , a new safari folder will be recreated on restarting the machine .

Files with the names you see are usually found in /System/Library/Caches but if Safari's running OK, I wouldn't worry about finding its cache file.

The path bar in Finder may make it easier to follow : click the view menu & choose Show Path Bar

or Right (ctrl or two finger) click the icon right at the top of the Finder window to see the path, and switch levels by clicking the one you want.

You are welcome. Were you in the User Library when looking for Library/Caches/com.apple.Safari/Cache.db?

I'm still not sure you are looking in your user library per the instructions I posted above.

Yes. Sorry, I didn't notice you were on Yosemite.

Safari (top menu) > clear website date and clear caches > All history > Clear History.

Then back to Safari > preferences > Remove all website date.

Then back to top menu > Develop > Empty caches.

I hope that's right; I don't have that OS any more.