Credit: Apple

Apple has taken the wraps off of its next-generation operating system updates at its Worldwide Developers Conference today, including iOS 27, iPadOS 27, and macOS 27 Golden Gate. And while the long-awaited Siri AI update is the headliner, Apple also emphasized its efforts to optimize its software, improving its performance and reliability.

For starters, the company is continuing to refine the Liquid Glass design language that it introduced last year. A slider in the Settings will allow users fine-grained control over the translucency of the Liquid Glass effect, ranging from maximally transparent and glassy to fully tinted. Last year’s redesigned icons are also being re-redesigned with more glass layers, which Apple says will make them sharper and more distinctive.

On macOS, Apple has also changed the way app toolbars and sidebars work, making toolbars more distinct, making the contents of sidebars extend all the way to the edge of the window, and reintroducing color to sidebar icons. Mac windows are also getting a “tighter corner radius,” to address complaints about the way window resizing works in macOS 26 Tahoe.

App toolbars are getting a more defined appearance in macOS 27 Golden Gate.
Credit: Apple

Apple has also rebuilt how search works across its operating systems. Updated indexing in Spotlight, Mail, and Photos should make them find both new and old content more reliably.

Parental controls are being spruced up in these updates, too, likely driven in part by age verification laws being introduced in some countries and US states. The Screen Time app is getting a design update, and developers are being given additional APIs for parental controls and customizing the way their apps behave based on the user’s declared age. Parents will have more control over users their kids can communicate with, the apps they can download, and the amount of time they can use each app.

Under the hood, Apple says it has optimized memory usage, CPU utilization, display rendering, and networking performance across all of its operating systems. CPU scheduler improvements introduced on newer iPhones have been backported to older models, which Apple says should make iOS 27 feel faster on older devices—like iOS 26, the iOS 27 update will run on phones as old as 2019’s iPhone 11.

Apple highlighted several performance and reliability improvements enabled by these and other optimizations. The company says apps should launch as much as 30 percent faster; newly shot photos should appear in your library up to 70 percent faster; and using AirDrop to transfer a file should be as much as 8 percent faster. Apple also said it has made the handoff between Wi-Fi and cellular networks more reliable.

Apple will make beta versions of these OS updates available to developers today and will refine those betas over the next few months before releasing the final versions this fall.