Safari for Mac
Safari is included with your Mac operating system.
To keep Safari up to date for the version of macOS you're using, use the App Store to install the latest macOS updates.
The most recent version of macOS includes the most recent version of Safari. For some earlier versions of macOS, Safari might also be available separately from the Updates tab of the App Store.
Before reinstalling, you might want to use Spotlight to search for Safari on your Mac. If you find it, but it's no longer in your Dock, just drag it to the Dock to add it back.
Safari for Windows
Apple no longer offers Safari updates for Windows. Safari 5.1.7 for Windows was the last version made for Windows, and it is now outdated.