Apple has just released iOS 18, available for download for eligible iPhones for free in the Software Update settings. If you’re considering purchasing one of the new iPhone 16 or iPhone 16 Pro models set to launch on September 20, they will come pre-installed with iOS 18. However, not all iPhones will be able to run iOS 18, and even those that can may not have access to all the new Apple Intelligence features. Each year, some older iPhone models are removed from Apple’s eligibility list for iOS updates, as was the case last year with the iPhone 8, iPhone 8 Plus, and iPhone X. Some older hardware may receive major new features, such as a firmware update for AirPods Pro 2 that turns them into a hearing aid, pending FDA authorization later this year. For a comprehensive list of all new iOS 18 features, check out Apple’s PDF list or reviews from MacRumors. Compatibility with iOS 18 depends on whether your iPhone was eligible for iOS 17 last year, and while older iPhones can continue to function without the latest features, they won’t be able to upgrade to the latest iOS. Apple Intelligence features will start rolling out in October for select devices, with additional language support coming next year. The new iOS 18 features include a Passwords app, enhanced Messages capabilities, an organized Photos app, and a personalized home screen layout, among others. MacOS Sequoia, iPadOS 18, WatchOS 11, and tvOS 18 are also available for download on other Apple devices._additional developments include new firmware for AirPods Pro earbuds and the availability of iOS 18 and Apple Intelligence.