Apple rolls out fourth developer & public beta of iOS 12.1.3, fourth developer beta of macOS 10.14.3

Apple has deployed the latest iOS beta for both its developer and public testing builds, with participants in either program now able to update to the fourth build.

Developers taking part in the test program can download the latest build via the Apple Developer Center, or as an over-the-air update on enrolled iOS devices. For the first time in this cycle, participants in the public Apple Beta Software Program are getting the iOS update at the same time as the developer release — but the macOS version remains limited to developers.

The fourth iOS beta, build 16D5039a, replaces build 16D5037a that was issued just three days ago on January 7, while macOS 10.14.3's fourth build of 18D39a replaces the third build, 18D38a.

As has been the case for this series of betas, the updates appear to be largely made up of incremental improvements, including bug fixes and performance enhancements rather than adding new features.

AppleInsider, and Apple itself, strongly recommend users don't install the betas on to "mission-critical" or primary devices, as there is the remote possibility of data loss or other issues. Instead, testers should install betas onto secondary or non-essential devices, and to make sure there are sufficient backups of important data before updating.

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