How to Add Face ID/Biometric Login to Your Expo+Clerk App

Biometric authentication on mobile devices offers a fast, convenient alternative to traditional password entry, which is often slow and error-prone on small keyboards. With the growing adoption of biometric technology—81% of smartphones have biometrics enabled—users can authenticate quickly using features like Face ID or fingerprint recognition. This shift has significant implications for user experience, as demonstrated by Descope's report that 48% of users abandon purchases due to forgotten passwords and Baymard Institute's finding of a 70.19% cart abandonment rate. By implementing biometric and passwordless login, apps have seen authentication success rates improve significantly, as seen in MojoAuth's analysis of over 523 million authentication events. This tutorial guides developers in integrating biometric login into an Expo app using Clerk's useLocalCredentials() hook, enabling users to sign in with biometrics after an initial email and password entry. It also discusses the differences between local credential storage and passkeys, along with platform-specific considerations for iOS and Android, including challenges like handling biometric enrollment changes and ensuring data security. The document compares various authentication providers, highlighting Clerk's unique offering of a dedicated biometric management hook in Expo, while also addressing common troubleshooting issues and best practices for secure credential storage.