Using Face ID or Touch ID has minimal impact on app frame rate and memory. The biometric system runs on a secure, dedicated chip, so it does not slow down your app's UI rendering. Battery usage is very low because authentication happens quickly and efficiently.
To keep your app smooth at 60fps, avoid blocking the main thread during biometric checks. Use asynchronous calls to the LocalAuthentication framework. Show a simple loading indicator if needed, and handle errors gracefully to avoid UI freezes.
Integrating Face ID or Touch ID requires only the LocalAuthentication framework, which is part of iOS. This adds no extra size to your app bundle. Startup time is unaffected since biometric checks happen on demand, not at launch.
On iOS, Face ID and Touch ID use the LocalAuthentication framework with strict privacy rules. Android uses the BiometricPrompt API, which supports various sensors but may vary by device. iOS requires user permission and shows system UI for authentication, while Android offers more customization but must handle device differences.
Your app takes 5 seconds to load the biometric authentication screen. What's likely wrong?
Answer: You are probably performing biometric checks or UI updates on the main thread synchronously. Use asynchronous calls and avoid blocking UI to fix this.