Short answer: build new iOS apps in SwiftUI if they support iOS 17 or later, and drop into UIKit for the few screens that need it. Keep existing UIKit apps in UIKit and move to SwiftUI one screen at a time, starting with new features. Most production apps in 2026 use both.
I have written iOS apps in UIKit since before SwiftUI existed and in SwiftUI since it shipped, and the question I get from clients is rarely “which is better”. It is “which one should this app use, given the team, the users’ iOS versions and what the screens need to do”. That is what this guide answers.
If you already have a UIKit app and want the step-by-step plan for moving it, that is in my UIKit to SwiftUI migration playbook. This page is the decision that comes before it.
SwiftUI vs UIKit at a Glance
| Concern | SwiftUI | UIKit |
|---|---|---|
| Style | Declarative: describe the UI for a given state | Imperative: create views and update them yourself |
| Speed of building standard screens | Faster, much less code | Slower, more boilerplate |
| Fine control over layout and behaviour | Good and improving; some gaps | Complete |
| Previews | Live Xcode previews for every view | Possible with the #Preview macro, less natural |
| Other Apple platforms | One framework for iOS, iPadOS, macOS, watchOS, tvOS and visionOS | iOS, iPadOS, tvOS and visionOS; AppKit on the Mac |
| New Apple features | Usually arrive here first; widgets and Live Activities are SwiftUI only | Still added, sometimes later |
| Older iOS versions | Best on iOS 17 and later | Works on anything |
| Debugging | Harder when state causes unexpected redraws | Predictable and well documented |
Where SwiftUI Is the Better Choice
- New apps on iOS 17 or later. NavigationStack, the Observation framework with
@Observable, SwiftData and the newer scroll and layout APIs cover what most apps need, without the workarounds older SwiftUI versions required. - Standard product screens. Forms, settings, lists, detail views, onboarding and dashboards take a fraction of the code they take in UIKit, and are easier to change when the design changes.
- Widgets, Live Activities and watchOS. WidgetKit and Live Activities are built in SwiftUI, and a watch app is SwiftUI in practice, so the team needs it either way.
- Small teams that move fast. Live previews and less code mean shorter feedback loops, which matters most in an MVP.
- Apps across Apple platforms. One UI framework for iPhone, iPad, Mac and Vision Pro, with per-platform adjustments rather than separate code.
Where UIKit Still Wins
- Large, highly custom collection layouts. UICollectionView with compositional layouts and diffable data sources still gives the most control and the most predictable performance for big, complex grids.
- Advanced text editing. Rich text editors, custom text input and detailed control of selection and the keyboard are still easier with UITextView and TextKit.
- Camera, scanning and custom media views. AVFoundation previews and custom capture interfaces are usually UIKit views wrapped for SwiftUI.
- Precise gesture and transition control. Interactive custom transitions and complex gesture handling are more mature in UIKit.
- Apps that must support old iOS versions. If a meaningful share of users is below iOS 16, many SwiftUI APIs you would want are unavailable, and UIKit is the safer base.
- Large existing UIKit codebases. A rewrite rarely pays for itself. Keep UIKit and add SwiftUI where it helps.
Using SwiftUI and UIKit Together
The choice is not either-or. Apple built clean bridges in both directions, and most apps I work on use both:
UIHostingControllerputs a SwiftUI view inside a UIKit app. This is how new features get built in SwiftUI without touching the rest of the app.UIViewRepresentableandUIViewControllerRepresentableput a UIKit view inside SwiftUI, for the camera preview, a map overlay or a rich text editor.- Shared models work in both. An
@Observableclass can drive a SwiftUI view and a UIKit view controller, so the data layer does not need to change when screens move.
A practical default for a new app: SwiftUI for the app structure and most screens, UIKit wrapped for the two or three screens that need it. For an existing app: UIKit for the structure, SwiftUI for new screens, and older screens moved when they need a redesign anyway.
How the Choice Affects Cost and Hiring
For a typical app of mostly standard screens, SwiftUI cuts UI build time noticeably, and changes after launch are cheaper too. The saving is smaller on apps dominated by custom interfaces, and it turns into extra cost if the app has to support old iOS versions and needs workarounds.
On hiring, most iOS developers in 2026 know both, but depth differs. Developers who started recently may be weak in UIKit; long-time developers may still write SwiftUI the UIKit way, with too much state in one place. For a mixed app, ask candidates how they would bridge a UIKit view into SwiftUI and how they would share state between the two. How framework choice fits the wider budget is covered in what an iOS app costs.
A Simple Decision Guide
- New app, iOS 17 or later: SwiftUI, with UIKit wrapped where a screen needs it.
- New app that must support iOS 15 or earlier: UIKit for structure, SwiftUI for simple screens.
- Existing UIKit app that works: keep it, and build new features in SwiftUI.
- Existing UIKit app that is hard to change: plan a gradual migration, screen by screen, with a clear order; see SwiftUI development and migration.
- App mostly built around a camera, editor or complex grid: UIKit at the core, SwiftUI for the surrounding screens.
