When you use Private Browsing windows, Safari doesn’t save your browsing history, and it asks websites you visit not to track you.
Use Private Browsing: Choose File > New Private Window, or switch to a Safari window that’s already using Private Browsing. A window that’s using Private Browsing has a dark address and search field with white text.
When you use a Private Browsing window:
Each tab in the window is isolated from the others, so websites you view in one tab can’t track your browsing in other tabs.
Safari doesn’t remember the webpages you visit or your AutoFill information.
Safari doesn’t store your open webpages in iCloud, so they aren’t shown when you view all your open tabs from other devices.
Your recent searches aren’t included in the results list when you use the address and search field.
Items you download aren’t included in the downloads list. (The items do remain on your computer.)
If you use Handoff, Private Browsing windows are not passed to your iOS devices or other Mac computers.
Safari doesn’t remember changes to your cookies or other website data. Safari also asks websites and others who provide those sites with content (including advertisers) not to keep track of your browsing, although it is up to the websites to honor this request.
Plug-ins that support Private Browsing stop storing cookies and other tracking information.
Websites can’t modify information stored on your device, so services normally available at such sites may work differently until you turn off Private Browsing.
Note: None of the above applies in other Safari windows you may have open that don’t use Private Browsing.
Stop using Private Browsing: Close the Private Browsing window, switch to a different Safari window that isn’t using Private Browsing, or choose File > New Window to open a window that doesn’t use Private Browsing. To further enhance privacy:
Delete any items you downloaded while using Private Browsing windows.
Close any other Private Browsing windows that are still open, to prevent others from using the Back and Forward buttons to see pages you visited in them.
Besides using Private Browsing windows, you can manage cookies and data stored by all websites and have Safari ask all websites not to track you.
If you forget to use a Private Browsing window, you can clear your browsing history.