Apple - How to clear the cache or do a hard refresh in Safari?
Go to Safari > Empty Cache, or hit ⌘ Command+⌥ Option+E. To refresh, click the refresh button on the addressbar or press ⌘ Command+R.
Another tip. If you want to restore Safari, like completely clear all the caches, or parts of it, go to Safari > Reset Safari. I use it usually when I need to clear a lot of memory from Safari, for it will clear the webpage screenshots, the cookies, the favicons, etc.
Edit: On the latest version of Empty Cache isn't on the Safari menu any more. It's now on the Develop menu. To show the Develop menu it, go to Safari > Preferences..., click the Advanced tab, and check Show Develop menu in menu bar. The keyboard shortcut remains unchanged, though.
Safari > Reset Safari isn't an option any more. To clear history you can use History > Clear History... and to clear cookies/local storage data, go to Safari > Preferences..., click the Privacy tab, and either click Remove All Website Data... or Details... to view and remove it for individual sites.
⇧ Shift and clicking the Refresh button generally does a full refresh. You can also empty cache with ⌘ Command+E, and then refresh.
If you haven't already, enable developer tools: open settings (Cmd + ,), go to the advanced tab, and check the box that says "Show Develop menu in menu bar."
Empty caches a single time: Develop > Empty Caches
Keyboard shortcut to empty caches a single time: Opt + Cmd + E
If you want to disable caching (for example, if you are developing a website and need to consistently reload changes to files on your site) you can do so: Develop > Disable Caches. Select this option again to reenable caching.
Note: for Safari 11 the disable caching feature was moved to the Network section of the web inspector. Open the web inspector with Cmd + Shift + I, go to the Network tab, and click the icon on the far right that looks like this:
