Apple's fourth developer betas of iOS 26.1, iPadOS 26.1, macOS 26.1 Tahoe, watchOS 26.1, tvOS 26.1, and visionOS 26.1 are out, as its testing program rolls on.

The fourth developer betas are now available, following after the third which were seeded on October 13. The second round arrived on October 6, and the first round landed on September 22.

The October 20 betas were seeded about an hour later than the usual time. This is most probably due to the outage of Amazon Web Services affecting huge swathes of the Internet earlier in the day.

The betas are for the first major update of Apple's milestone operating system versions, consisting of iOS 26, iPadOS 26, watchOS 26, macOS 26 Tahoe, visionOS 26, and tvOS 26.

  • iOS 26.1 beta 4 is build 23B5073a, replacing 23B5064e
  • iPadOS 26.1 beta 4 is build 23B5073a, replacing 23B5064e
  • watchOS 26.1 beta 4 is build 23S5031a, replacing 23S5022e
  • macOS Tahoe 26.1 beta 4 is build 25B5072a, replacing 25B5062e
  • visionOS 26 26.1 beta 4 is build 23N5042a, replacing 23N5033d
  • tvOS 26 26.1 beta 4 is build 23J5571a, replacing 23J5563d

In the first beta build of iOS 26.1, Apple updated Apple Intelligence with support for more languages, including Live Translation in Chinese (Traditional and Simplified), Japanese, and Korean. The first signs of Model Context Protocol (MCP) support were also spotted, which could eventually help AI systems to interact with data on the device more effectively, through a single standard interface.

There were also "Background Security Improvements" instead of "Rapid Security Response" updates, a Liquid Glass improvement to the dialer's keypad and the Photos video scrubber, full-color tags in Calendar, a wider tab bar in Safari, and swiping to change tracks in Apple Music.

The third developer beta for iOS 26.1 included a new Apple TV icon, settings for a Notification Forwarding feature, and references to unreleased wallpaper. There were also references to expanded support of third-party AI services beyond ChatGPT, as well as an expansion of Local Capturen from iPadOS to iOS.

AppleInsider and Apple strongly warn against users installing test operating systems or beta software onto "mission-critical" hardware, due to the persistent risk of data loss. beta participants should use secondary or less critical hardware for beta testing, and have sufficient backups of their data at all times.

A public beta is usually introduced a short time after the developer version, which non-developers should use instead of the developer beta. This is due to it having features that have already been tested by developers, and are generally safer to use.

Find any changes in the new builds? Reach out to us on Twitter at @AppleInsider or @Andrew_OSU, or send Andrew an email at [email protected].