Passwordless authentication is a way of logging in where a user no longer enters a password, but instead identifies themselves with a fingerprint, facial recognition, hardware token, or a cryptographic key stored securely on the device. For entrepreneurs and website administrators, this means less risk of password leaks and phishing, a smoother user experience, and fewer support requests about forgotten passwords. This article explains how it works and how to implement it step by step.
What is passwordless authentication
With traditional authentication, a user proves their identity by sharing a secret (the password) with the server. That secret can be stolen, guessed, or phished. Passwordless authentication works differently: the user’s device generates a key pair. The public key is stored on the server, while the private key never leaves the device. Logging in means the device proves it possesses the corresponding private key, without ever sending it.
The result: there is no longer a password that can be stolen during a data breach, and phishing pages have nothing to capture. For users, it also feels faster than typing a password and possibly entering a second factor.
WebAuthn and FIDO2 as the technical foundation
The technical standard behind passwordless login on the web is WebAuthn (Web Authentication API), developed within the W3C and part of the broader FIDO2 specification. FIDO2 consists of two components: WebAuthn handles communication between the browser and server, while CTAP (Client-to-Authenticator Protocol) manages communication with external authenticators such as USB keys. All major browsers support WebAuthn, making implementation on desktop and mobile well feasible.
| Method | Security | Ease of use |
|---|---|---|
| Password | Low | Moderate |
| WebAuthn + biometrics | High | High |
| Hardware token | High | Moderate |
| SMS code | Moderate | Low |
Implementing step by step
A working implementation is built in a fixed order. The steps below apply regardless of the programming language your web application is written in.
Prepare database and library
Extend your user table with fields for credential ID, public key, and metadata such as authenticator type. Choose a proven WebAuthn library for your language (for example for Node.js, Python, or Java) instead of writing your own cryptography.
Build a registration endpoint
Create an endpoint that generates a unique challenge during registration. Store it temporarily server-side to prevent replay attacks, and link the resulting credential to the user account.
Client-side integration
Use navigator.credentials.create() for registration and navigator.credentials.get() for logging in itself. The browser handles communication with biometrics or a hardware token.
Testing and rollout
Test on multiple devices and browsers, build clear error handling, and offer a fallback for users who don’t (yet) have a supported device.
Security, fallback, and hosting
WebAuthn only works over a secure HTTPS connection; without a valid SSL certificate, the browser refuses the API. So make sure your hosting environment automatically handles SSL, so you don’t have to manage it manually. Also take into account users on older devices that don’t support biometrics or hardware tokens: offer a clear alternative, such as a magic link sent via email.
Since email is often the fallback route for account recovery, reliable business email hosting with a good security score is important. If you manage your application through Plesk, you’ll find SSL settings and certificates clearly organized in the Plesk panel of your web hosting environment. If you’re unsure whether your current hosting provider supports this well, check out the options to switch to Tandata.
Frequently Asked Questions
Is passwordless authentication the same as two-factor authentication?
No. Two-factor authentication adds an extra step in addition to a password. Passwordless authentication completely replaces the password with a cryptographic key or biometrics.
Does WebAuthn work on all browsers and devices?
Most modern browsers and operating systems support WebAuthn, but older devices may have limitations. Therefore, always offer a fallback method.
Is an SSL certificate required for passwordless login?
Yes, WebAuthn only works over HTTPS. Without a valid certificate, the browser cannot use the authentication API.
What happens if a user loses their device?
Ensure there’s a recovery procedure, for example via a verified email address or a second registered device, so the user can regain access.
Conclusion
Passwordless authentication makes logging in safer and more pleasant by replacing passwords with cryptographic keys and biometrics via the WebAuthn standard. Start with a well-prepared database and library, carefully build registration and authentication steps, test broadly, and keep a fallback in reserve. A reliable hosting environment with standard SSL makes implementation much easier.