Apple has officially advanced its developer beta program and launched the fourth round of beta builds of iOS 27, macOS 27, tvOS 27, watchOS 27, visionOS 27, and iPadOS 27 for developers. Currently, users participating in the Apple Developer Program can already download and experience these latest system builds through their devices.
Looking back at the recent update rhythm, the first round of developer beta versions of major operating systems debuted on June 8; subsequently, the second round of beta versions were launched on June 22, with the corresponding versions of watchOS 27 later, released on June 23 and June 25; the third round of beta versions was officially launched on July 6.
In the latest fourth round of testing, the specific build version numbers of each system have been adjusted as follows: the beta 4 version number of iOS 27 and iPadOS 27 has been updated to 24A5390f (previously 24A5380h); macOS 27 beta 4 has been updated to 26A5388g (previously 26A5378j); tvOS 27 beta 4 has been updated to 24J5325d (previously 24J5315i); watchOS 27 beta 4 updated to 24R5325h (previously 24R5315i); visionOS 27 beta 4 updated to 24M5326g (previously 24M5316k).
Looking back at previous iterations of the system, early major adjustments include fine-tuning of Liquid Glass, the much-anticipated comprehensive upgrade of Siri, child protection features, and many detailed improvements. A subsequent second update introduced a connected HomePod or HomePod mini-like presentation for Apple TV in the Home app, and a new non-functional Insights option was added to the Apple Wallet app. Version 3 brings more visual tweaks and adds customization options for Siri AI for newer iPhone models.
Since the early developer beta software is still in the active development stage, there is a higher chance of bugs, crashes, and potential instability. Therefore, users participating in the test should try to install the system on a backup device or non-main machine to avoid risks. These early versions for developers are intended to help developers become familiar with and adapt to new changes in the operating system before the product is officially released to the public later in 2026, and are therefore not suitable for ordinary consumers to try out. For the general public, it is a safer choice to wait for the subsequent launch of the public beta version.