Apple Rolls Out macOS 27 Developer Beta 4 to Testers

Apple pushed macOS 27 developer beta 4 to registered testers Tuesday, delivering build 26A5388g fourteen days after the previous beta landed.

The cadence is consistent — two weeks between beta drops, which puts Apple roughly on schedule for a public debut alongside new Mac hardware this fall. Beta 4 in a major macOS cycle typically means the feature set is locked and the team is grinding through remaining bugs before the Release Candidate phase.

Registered developers can grab the update through System Settings under General > Software Update, flipping the Beta Updates toggle to pull it down. Public beta testers need to enroll through the Apple Beta Software Program first, then the same Settings path surfaces the option.

The beta history so far: Beta 3 arrived July 7 (build 26A5378j), Beta 2 on June 23 (26A5368g), and the initial Beta 1 on June 9 (26A5353q). Each build has been roughly two weeks apart, a steady tempo that suggests Apple is comfortable with the release trajectory.

As with any pre-release build, expect rough edges. Apple recommends installing on a secondary machine rather than your primary workhorse. Beta 4 is generally more stable than earlier builds — by this point in the cycle, most major API changes are behind them and the focus shifts to polish and performance.

What actually changed in Beta 4 remains unclear at this point. Apple’s release notes are typically sparse for mid-cycle betas, and the developer community will likely surface any notable tweaks over the next day or two as builders dig through the build.

If you’re already on the macOS 27 train, the update should show up in Software Update. If you’ve been waiting — Beta 4 is usually a safe entry point for adventurous users with good backups.