Update iOS on iPhone
When you update to the latest version of iOS, your data and settings remain unchanged.
Note: Before you update, set up iPhone to back up automatically, or back up your device manually.
Update iPhone automatically
If you didn’t turn on automatic updates when you first set up iPhone, go to Settings > General > Software Update > Automatic Updates, then turn on Automatic Updates.
iPhone automatically installs updates wirelessly, and you’re notified before the update occurs. To see the currently installed version of iOS, go to Settings > General > Software Update.
Update iPhone manually
Go to Settings > General > Software Update > Automatic Updates, then turn off Automatic Updates.
At any time, you can check for and install software updates. Go to Settings > General > Software Update. The screen shows the currently installed version of iOS and whether an update is available.
Update using your computer
Do one of the following:
In the Finder sidebar on your Mac: Select your iPhone, then click General at the top of the window.
Note: To use the Finder to update your iPhone, macOS Catalina is required. With earlier versions of macOS, use iTunes to update your iPhone.
In the iTunes app on a Windows PC: Click the iPhone button near the top left of the iTunes window, then click Summary.
Click Check for Update.
To install an available update, click Update.
See the Apple Support articles Update to the latest iOS and If you can’t update or restore your iPhone, iPad, or iPod touch.