Is SwiftUI finally as fast as UIKit in iOS 26?
Article Summary
Jacob Bartlett puts SwiftUI and UIKit through the ultimate stress test: a feed of 22,000 animated GIFs running at 120fps. The results might surprise you.
After years of 'yes, but' answers about SwiftUI's production readiness, iOS 26 promises major scroll performance improvements. Bartlett built identical chaotic UIs in both frameworks (high-res images, autoplaying animations, variable-sized cells, complex gestures) to scientifically measure whether SwiftUI has finally caught up to UIKit's performance.
Key Takeaways
- Ice Cubes app saw substantial scroll hitch rate drop after iOS 26 SDK update
- Apple dedicated half of WWDC 2025 SwiftUI session to List performance improvements
- Test uses 120fps refresh rate giving just 8.33ms per frame to render
- Performance remains the final bastion of native iOS supremacy over cross-platform tools
iOS 26 brings significant SwiftUI scroll performance improvements, but the full head-to-head comparison with UIKit reveals whether it's truly reached parity.
About This Article
Jacob Bartlett needed to design a stress test that would actually show the performance differences between SwiftUI and UIKit. He needed high-resolution images, complex view hierarchies with gradients, animations that never stopped, cells of different sizes, and multi-gesture interactions that updated data as things happened.
Bartlett pulled 22,000 animated GIFs from a 2001 CD-ROM archive and built the same chaotic UIs in both frameworks. He forced the screen to hit 120fps refresh rates with only 8.33ms per frame to render. There was no room to hide performance problems.
The comparison showed whether iOS 26's scroll performance improvements, which Apple spent half of WWDC 2025's SwiftUI session talking about, actually matched what UIKit could do on feeds with lots of scrolling.