Apple has released the fourth round of developer betas for its 26-generation operating systems, including iOS 26.4, iPadOS 26.4, watchOS 26.4, tvOS 26.4, visionOS 26.4, and macOS Tahoe 26.4. This follows the third round that landed on March 2 for most platforms, with macOS arriving a day later on March 3.

Each operating system received build 4 with updated version numbers: iOS 26.4 build 23E5234a, iPadOS 26.4 build 23E5234a, watchOS 26.4 build 23T5236a, visionOS 26.4 build 23O5235a, tvOS 26.4 build 23L5234a, and macOS Tahoe 26.4 build 25E5233c. These replace previous builds from the third beta round.

The first iOS 26.4 developer beta included changes to Apple Podcasts, Apple Music, end-to-end encryption for RCS, and Stolen Device Protection activation. Later builds added a switch from iBoot to mBoot for the iPhone bootloader and a new average bedtime metric in Apple Health.