According to French website iPhoneSoft.fr, iOS 19 will support all iPhone models currently running iOS 18. This information is cited from an internal source at Apple.
This means iOS 19 will be compatible with the following iPhone models:
iPhone 16 series: iPhone 16, 16 Plus, 16 Pro, 16 Pro Max
iPhone 15 series: iPhone 15, 15 Plus, 15 Pro, 15 Pro Max
iPhone 14 series: iPhone 14, 14 Plus, 14 Pro, 14 Pro Max
iPhone 13 series: iPhone 13, 13 mini, 13 Pro, 13 Pro Max
iPhone 12 series: iPhone 12, 12 mini, 12 Pro, 12 Pro Max
iPhone 11 series: iPhone 11, 11 Pro, 11 Pro Max
iPhone XS series: iPhone XS, XS Max
iPhone XR
iPhone SE (2nd generation and later)
In the list above, the oldest iPhone models are the iPhone XS, XS Max, and XR, which were launched in September 2018.
However, some new features on iOS 19 may not be available on older devices.
If this information is accurate, this will be the second year in a row that Apple has not removed any iPhone models in a new iOS update. Previously, iOS 18 also supported all devices running iOS 17, while iOS 17 dropped support for the iPhone 8, iPhone 8 Plus, and iPhone X.
Meanwhile, with iPadOS 19, there will be some changes as the iPad 7 (released in 2019) will no longer be supported. However, other iPad models running iPadOS 18 will continue to be compatible with the new version.
Apple is expected to release the first betas of iOS 19 and iPadOS 19 at WWDC 2025 in June, and the official update could be released in September of the same year. Some features such as Siri enhanced conversation capabilities, similar to ChatGPT, are expected to appear in the iOS 19.4 update around March 2026.