Fetching data from remote APIs affects app performance mainly through network latency and data processing time. Slow or unstable connections can cause delays, reducing the app's responsiveness. Excessive or unoptimized API calls can increase battery usage and memory consumption, especially if large data sets are downloaded or stored in memory.
To keep the app smooth at 60fps, minimize API calls by caching data locally when possible. Use asynchronous calls with Flutter's FutureBuilder or async/await to avoid blocking the UI thread. Compress data on the server side and paginate large data sets to reduce download size. Debounce user input to prevent unnecessary repeated calls.
API calls themselves do not increase app bundle size but can affect startup time if the app waits for data before showing UI. To improve startup speed, load essential UI first and fetch data in the background. Avoid bundling large static data inside the app; fetch it remotely to keep the app size small.
Both platforms support network calls similarly in Flutter, but Android requires permissions in the AndroidManifest.xml file, while iOS does not require explicit permission for network access. iOS apps may be more sensitive to background fetch restrictions, so optimize API calls accordingly. Android devices vary more in network hardware, so test on multiple devices.
Apple App Store requires apps to handle network errors gracefully and not crash if data is unavailable. Google Play expects apps to respect user data privacy and use secure connections (HTTPS). Both stores require clear user consent if personal data is fetched or stored. Avoid excessive background network usage to comply with battery usage policies.
Your app takes 5 seconds to load this screen. What's likely wrong?