29 March 2019
It is a new month which means it is time for Apple to push out the latest beta releases for its different operating systems. This includes iOS 12.4 fourth beta, tvOS 12.4 third beta, macOS 10.14.6 second beta, and watchOS 5.3 third beta. The latest builds have been released within two weeks of the previous beta release.
The build number for iOS 12.4 beta 4 is 16G5046d, macOS 10.14.6 beta 2 is 18G48f, tvOS 10.14.6 beta 2 is 16M5545c, and watchOS 5.3 beta 3 is 16U5545c. These are developer beta builds which means they will be available via the Apple Developer website. You will also need to have an Apple developer account to get access to these betas. For those who already using a developer beta build, the new versions should arrive as an OTA update anytime soon.
If you don't have a developer account and also don't want to get one, you can still wait for Apple to release public betas. These are usually made available soon after the developer builds. Once they become available, you will be able to get them via the Apple beta program. But regardless of whether you go for a developer or public beta, it is advised to install it on a spare device instead of your daily driver.
As far as changes included in the latest beta are concerned, these are mostly about performance improvements, bug fixes, and preparing for upcoming major features. It means the latest betas do not bring any new major changes or features.