Apple iOS 18.3 is compatible with all iPhones that can run iOS 18. This means all iPhones from the iPhone XS onwards, including the second- and third-generation iPhone SE models.

Apple made waves when it rolled out iOS 18 in fall, bringing a host of AI-powered features to iPhones thanks to Apple Intelligence. Initially, you had to opt into Apple Intelligence features. The latest update,

Apple has kicked off iOS 18.3, iPadOS 18.3, and MacOS 15.3 with one significant change affecting AI. Since its debut, Apple Intelligence has required the extra step of actually turning it on or opting in. But with the new versions, Apple's AI feature is enabled by default for eliglble devices.