Launch Settings on your iPhone and select General followed by Software Update. The Software Update page will show the latest available version of the iOS you're running. (Or, if you're up to date, it will show that you're up to date.) Below that, tap the link for the iOS 18 update.

Even if you don’t buy an iPhone 16, you can install iOS 18, which is out today, and start customizing your home screen in new ways, text high-res videos to your Android friends, and store your passwords in Apple’s slick new password manager. But as for all those AI features you may have heard so much about, those aren’t ready—at least, not yet.

Enough to make you feel you have a brand-new iPhone. Note, though, that one of the biggest things in iOS 18 is the introduction of Apple Intelligence, though it won’t be available in this release. When it arrives, it will be for iPhone 16 series, iPhone 15 Pro and iPhone 15 Pro Max handsets only.