Resetting the Xcode Preview for a Clean Environment

When working with SwiftUI previews, Xcode occasionally misbehaves—showing stale views, outdated data, or even refusing to render your preview entirely. This usually happens because previews are powered by a hidden simulator environment that can retain state across builds.

The good news? You can easily reset this preview system using a command Apple introduced in Xcode 15:

📼 Reset SwiftUI Previews

To wipe the preview simulator and start fresh, run the following command in your terminal:

xcrun simctl --set previews delete all

This command deletes all preview-specific simulators created and cached by Xcode. It’s safe, fast, and often resolves the “Preview not updating” or “Stuck loading” issues.

💡 You don’t need to restart Xcode afterward, but rebuilding your preview (⌘ + Option + P) is a good idea.

🛠️ When Should You Use This?

• Previews are stuck or crash every time
• Data doesn’t reflect your latest changes
• Environment variables or devices aren’t behaving as expected
• You’ve updated Core Data, SwiftData, or iCloud settings in your app

🔁 Automate it (Optional)

If you run into this often, create a shortcut or alias in your shell config:

alias resetPreviews='xcrun simctl --set previews delete all'

Then just type resetPreviews whenever you want a clean slate.

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SwiftUI previews are powerful but can occasionally get messy behind the scenes. Now you know how to give them a quick refresh.

Happy previewing!