Passkeys offer a secure, passwordless authentication method that enhances user experience by utilizing public-key cryptography, which replaces traditional passwords with device-tied cryptographic credentials unlocked through biometrics or a PIN. This approach reduces risks associated with phishing and credential theft, as private keys never leave the device and only respond to challenges from the original domain. Implementing passkeys in applications like Next.js involves using WebAuthn challenges to manage registration and authentication flows, with the server storing only public keys, thus minimizing server-side liability. The process integrates smoothly with major platforms and devices, ensuring interoperability and multi-factor authentication by default. Tools like SimpleWebAuthn facilitate manual implementation, while services like Clerk simplify the setup with minimal code, offering a comprehensive user management solution that includes additional authentication methods and multi-tenancy support. By adopting passkeys, companies can enhance security, reduce support burdens, and streamline the sign-in process, focusing on innovation rather than the complexities of authentication management.