Using MainActor ensures UI updates happen on the main thread, preventing crashes and visual glitches. It helps maintain a smooth frame rate of 60fps by avoiding thread conflicts. However, blocking the main thread with heavy work can cause jank and dropped frames, hurting battery life and responsiveness.
Keep UI updates lightweight and quick on the MainActor. Move heavy tasks like data processing or network calls off the main thread using background actors or async tasks. Use await properly to avoid blocking the UI. This keeps animations smooth and the app responsive.
Using MainActor is a language feature and does not add significant size to your app bundle. It has no direct impact on startup time. Proper use can improve perceived startup speed by preventing UI freezes during initial loading.
On iOS, MainActor is a Swift concurrency feature that guarantees UI code runs on the main thread. Android uses the Looper and Handler system to post UI updates on the main thread. Both platforms require UI updates on their main thread but use different APIs and concurrency models.
Apple requires apps to be stable and responsive. Using MainActor correctly helps avoid crashes from UI thread violations, meeting Apple's stability guidelines. Ensure your app does not block the main thread for long periods, as this can cause app termination during review.
Your app takes 5 seconds to load this screen. What's likely wrong?
MainActor blocking the UI thread.MainActor.