SwiftUI Preview Tools to Speed Up Development 2025

Home
Blog
Speed Up SwiftUI Development: Preview...

TL;DR:

Preview across multiple devices at once instead of switching simulators manually
Test Light Mode, Dark Mode, and Dynamic Type for accessibility early
Use mock data instead of real API calls to keep previews fast and safe
When previews freeze, force hot reload (Cmd + Option + P) or tweak minor UI
Debug layouts using temporary borders and background overlays
Create reusable preview modifiers to avoid repeating boilerplate
Simulate different view states like Loading, Error, or Empty with Groups
(Advanced) Automate preview snapshots in CI for consistent UI testing

Introduction

SwiftUI Previews are more than just a visual gimmick—they’re a development superpower. Whether you’re an independent developer or part of a Mobile App Development Company, mastering these preview hacks can dramatically speed up your workflow, help you catch UI bugs early, and iterate with confidence.

Still hitting Run every time you tweak a button color or change padding? If so, you’re wasting crucial development time. SwiftUI Previews offer a real-time, interactive way to experiment, validate, and perfect designs without rebuilding your entire app.

In this blog, I’ll walk you through 8 essential SwiftUI Preview hacks that will make your development workflow smoother, faster, and more efficient.

What Are SwiftUI Previews (And Why You’re Underusing Them)?

SwiftUI Previews allow you to render SwiftUI views in real-time without needing to run the entire app. With Xcode’s canvas, you can visually test layouts, themes, and logic variations on the fly. But most developers just use the basic #Preview and miss out on the powerful capabilities SwiftUI Previews provide.

Let’s change that.

1. Preview Multiple Devices Simultaneously

Want to test your UI across iPhone SE, iPhone 14 Pro, and iPad Pro without switching simulators? Just stack previews:

#Preview("iPhone 14", traits: .device("iPhone 14")) {

    MyView()

}

#Preview("iPad Pro", traits: .device("iPad Pro (12.9-inch)")) {

    MyView()

}

Use this trick to make sure your design is responsive and scalable.

2. Preview in Light Mode, Dark Mode, and Dynamic Type

Check accessibility and color scheme compatibility with this quick hack:

Group {

    MyView()

        .preferredColorScheme(.light)

        .previewDisplayName("Light Mode")

    MyView()

        .preferredColorScheme(.dark)

        .previewDisplayName("Dark Mode")

    MyView()

        .environment(\.sizeCategory, .accessibilityExtraLarge)

        .previewDisplayName("Dynamic Type")

}

This helps you catch visual bugs early.

3. Use Mock Data Without Hitting APIs

Avoid network calls and use mock data in preview mode:

#if DEBUG

extension MyModel {

    static let preview = MyModel(name: "Preview User", age: 25)

}

#endif

#Preview {

    MyView(model: .preview)

}

Also, protect against preview-side effects:

if ProcessInfo.processInfo.environment["XCODE_RUNNING_FOR_PREVIEWS"] == "1" {

    // Load mock data

}

4. Force Hot Reload in Previews

Sometimes previews freeze. Don’t rebuild the app—trigger a manual refresh with:

Shortcut: Cmd + Option + P
Or make a tiny UI change like .padding(0.1) to trigger the refresh.

It’s fast and doesn’t waste your time on unnecessary compiles.

5. Debug Layouts with Borders and Backgrounds

This trick is great when you’re fighting with alignment or padding issues:

MyView()

    .border(Color.red)

    .background(Color.yellow.opacity(0.2))

Instant layout clarity!

6. Create Reusable Preview Modifiers

Avoid repetition with a custom view extension:

MyView()

    .border(Color.red)

    .background(Color.yellow.opacity(0.2))

Use it like:

MyView().previewBorder()

7. Preview Multiple App States (Loading, Empty, Error)

Preview all scenarios without changing your app logic:

Group {

    MyView(state: .loading).previewDisplayName("Loading")

    MyView(state: .empty).previewDisplayName("Empty")

    MyView(state: .error("Network Error")).previewDisplayName("Error")

}

Super useful for testing error handling UI.

8. Automate Preview Testing (Optional Advanced Tip)

Want to integrate previews into CI for UI consistency? Use xcodebuild to render previews or include preview screenshots in snapshot testing tools. It’s a power move for teams.

Conclusion

SwiftUI Previews are one of the fastest ways to speed up UI iteration and eliminate guesswork. Instead of constantly rebuilding your app, use previews to test layouts, themes, and states instantly. Whether you’re an indie developer or working in a Mobile App Development Company, make previews a core part of your workflow—and watch your development pace double.