Animations can make your app feel smooth and alive. However, complex or poorly optimized animations may reduce frame rates below 60fps, causing choppy visuals. They also use more CPU and GPU power, which can increase battery drain. Simple animations that run on the GPU and avoid heavy calculations keep performance high and battery use low.
Use Flutter's built-in animation widgets like AnimatedContainer or AnimatedOpacity for efficient animations. Avoid rebuilding large widget trees during animations. Use RepaintBoundary to isolate animated parts. Keep animations short and simple. Profile your app with Flutter DevTools to spot jank and optimize accordingly.
Animations themselves add minimal size if using Flutter's native widgets. However, including many custom animation assets (like large Lottie files or videos) can increase bundle size and slow startup. Optimize assets by compressing and only loading animations when needed to keep app size and startup time low.
Both iOS and Android support smooth animations, but Flutter handles them consistently across platforms. iOS devices often have ProMotion displays supporting up to 120fps, so animations can be extra smooth there. Android devices vary widely in hardware, so test animations on lower-end devices to ensure performance stays good.
Apple's App Store guidelines emphasize smooth, responsive UI and discourage apps that freeze or crash due to heavy animations. Google Play requires apps to maintain good performance and battery efficiency. Avoid animations that cause excessive battery drain or degrade user experience to pass reviews.
Heavy or unoptimized animations running during screen load can delay rendering. Large animation assets loading synchronously may block UI. Check if animations are causing main thread delays or if assets are too big. Optimize by deferring animations until after the screen is visible and compressing assets.