Choosing the right build configuration affects app speed and battery use. Debug builds run slower because they include extra tools for testing and debugging. Release builds are optimized for speed and use less memory, helping your app run smoothly at 60fps and saving battery life.
Use the flutter build ios --release command to create an optimized app. This removes debug symbols and enables compiler optimizations. Avoid running heavy tasks on the main thread to keep UI smooth.
Release builds are smaller because they exclude debug info and unused code. This reduces app download size and startup time. Enabling app thinning in Xcode helps deliver only needed assets for each device, further reducing size and speeding launch.
iOS uses Xcode build configurations: Debug, Release, and optionally Profile. Flutter integrates with Xcode for iOS builds. Android uses Gradle build types like debug and release. iOS requires code signing and provisioning profiles for release builds, while Android uses APK or AAB signing keys.
It is likely you are running a Debug build instead of a Release build. Debug builds include extra debugging tools and are not optimized, causing slow startup. Switch to a Release build and check if startup improves.