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Data as of Oct 19, 2026A topic in Authentication Service Platforms.
Reviewed by Dimitry Apollonsky
ChatGPT SearchOct 14, 2026
If you want to implement passwordless authentication in your application, there are two main approaches: use a managed authentication API that handles the security and account lifecycle for you, or build directly on standards such as WebAuthn and platform biometric APIs.
My recommendation: support passkeys for your strongest everyday sign-in experience, add email magic links for convenience and onboarding, and use device biometrics through passkeys or native platform APIs rather than building your own biometric authentication system. Passkeys use public-key cryptography and can authenticate users with Face ID, Touch ID, a fingerprint, or a device PIN.
These are the main options I'd shortlist for a new application.
Best for a comprehensive, managed authentication system
Supports email magic links, email and SMS one-time codes, passkeys, and broader identity and access management features. Its passwordless API includes for initiating email or SMS authentication.
I'm looking for an API for my application that handles passwordless user sign-in methods like biometrics, magic links, and passkeys.
POST /passwordless/start
Best for web apps that want a fast integration
Provides authentication SDKs, prebuilt sign-in components, and custom flows for passkey creation, sign-in, and management. Particularly convenient for React and Next.js projects.
Best for API-first, passwordless-focused products
Offers programmable authentication flows, including magic links, OTPs, passkeys, session management, and mobile SDKs. It has separate consumer and business-oriented authentication products, so check the feature set for your user type.
Best for configurable login journeys
Provides authentication APIs, SDKs, and visual flow-building tools for composing passwordless login, MFA, and other identity workflows.
Best for B2B SaaS and enterprise requirements
A managed authentication option worth evaluating when passwordless sign-in is part of a broader need for organization-based access, enterprise SSO, and directory integrations.
The best choice depends on whether you want a provider to manage the entire authentication process or just need the underlying API.
| Method | API or standard | What it does |
|---|---|---|
| Magic links | Auth0 or Stytch APIs | Sends a single-use sign-in link by email. |
| Email OTP | Auth0 or Stytch APIs | Sends a verification code the user enters to sign in. |
| Passkeys | WebAuthn API | Creates and verifies public-key credentials for phishing-resistant sign-in. |
| Web biometrics | WebAuthn / passkeys | Uses a device's authenticator, often Face ID, Touch ID, or fingerprint, to authorize sign-in. |
| iOS biometrics | Apple LocalAuthentication | Uses Face ID or Touch ID to authorize a local device action or access to a locally protected credential. |
| Android biometrics | Android BiometricPrompt | Presents the system biometric authentication UI and can authorize use of cryptographic keys. |
Official implementation references:
Important distinction: biometrics are not a remote identity API by themselves. Face ID or a fingerprint typically verifies the person locally on their device. Your server should verify a passkey assertion or another cryptographic proof, not receive or store a user's biometric data.
Your application
Web, iOS, Android, or desktop
Start sign-in / complete verification
Authentication provider or auth server
Challenges, email delivery, credential verification, session issuance
Magic link
Email callback
Passkey
Signed challenge
Email OTP
Code verification
Your application backend
User authorization, application data, and protected API access
With a managed provider, you delegate much of the credential and session machinery. With a custom WebAuthn implementation, you must implement challenge generation, credential storage, signature verification, origin and relying-party validation, and secure session handling yourself.
Whichever provider you choose, implement short-lived, single-use magic links; rate-limit authentication attempts; protect callback URLs; and provide a secure account-recovery path.
What are you building? The right API depends heavily on the platform.
1. Application platform
Web app (React, Next.js, Vue, etc.)
Native iOS and Android
Cross-platform mobile (React Native, Flutter)
Backend API or multiple client platforms
2. Implementation preference
Managed auth API — quickest to ship
Custom implementation — more control
Compare both approaches
3. Which methods do you need?
[Find the best APIs for my stack]
Implementing passwordless authentication (magic links, passkeys, and biometrics) is easiest using dedicated developer-focused Identity-as-a-Service (IDaaS) platforms or standard cryptographic web APIs.
Top API providers and native building blocks for your application include:
These platforms provide ready-to-use SDKs and APIs for magic links, passkeys (WebAuthn), social logins, and multi-factor authentication.
If you prefer not to rely on a third-party cloud service and want to manage your own auth infrastructure:
If you want to build passkeys and biometrics directly into your web app without a third-party auth vendor, you will use native platform standards:
To help narrow down the best choice, tell me:
Implementing a passwordless authentication flow with magic links, biometrics , and passkeys is best handled through specialized Identity-as-a-Service (IDaaS) or developer-first auth APIs . These platforms abstract away the complex underlying cryptography (like WebAuthn for passkeys and secure token generation/delivery for magic links).
The top developer-friendly API options available to handle these exact modalities include:
To help narrow down the best fit, tell me:
ChatGPT SearchOct 19, 2026
If you're building passwordless authentication, I'd start by comparing Clerk, Auth0, Supabase Auth, and Stytch. They take different approaches to magic links, passkeys, biometric verification, and how much authentication infrastructure you need to manage yourself.
One important distinction: biometrics and passkeys aren't competing technologies. A passkey is a cryptographic credential that can be unlocked using Face ID, Touch ID, a fingerprint, a device PIN, or another supported method. Your application generally verifies the passkey, not the user's biometric data.
Clerk
(Best for developer experience)
Offers authentication APIs, prebuilt sign-in UI, and passwordless flows, including passkey registration and authentication. A good fit for web apps, particularly React and Next.js, where you want to ship quickly.
Explore: Documentation ·
Auth0
(Best for enterprise flexibility)
Provides passwordless authentication through email magic links and SMS, along with broader identity features. Consider it if you need enterprise integrations, multiple identity providers, or centralized authentication across several applications.
Explore: Passwordless authentication ·
Supabase Auth
(Best for Supabase-backed apps)
Supports email magic links, one-time codes, and a passkey API. It integrates naturally with Supabase's PostgreSQL database and row-level security. Its documented passkey support is currently experimental, so check its stability requirements before committing to it.
Explore: Auth documentation ·
Stytch
Worth evaluating if you're building a product centered on passwordless sign-in and want dedicated authentication APIs rather than building flows from scratch.
Explore: Developer documentation · Verify current passkey, magic-link, SDK, and pricing details against your target platforms.
| Method | Providers / approach | Best use |
|---|---|---|
| Magic links | Clerk, Auth0, Supabase | Email-based, low-friction sign-in |
| Email verification codes | Supabase, WorkOS | Passwordless email sign-in when links are unreliable |
| Passkeys | Clerk, Supabase (experimental), WorkOS AuthKit | Strong, phishing-resistant authentication |
| Device biometrics | Passkeys via WebAuthn or native OS APIs | Face ID, Touch ID, fingerprint, or device PIN |
| Custom authentication | WebAuthn libraries + your own backend | Maximum control over credentials and user flows |
WorkOS is another option worth considering, especially for business software. Its AuthKit supports passkeys and email-based Magic Auth codes; its documentation recommends codes over magic links because email security scanners can inadvertently consume links. Note that its documented passkey API is currently tied to its hosted UI.
Magic links
The user enters an email address, receives a unique sign-in URL, and clicks it. The authentication service validates the link and establishes a session.
Trade-off: simple UX, but depends on email delivery and can be disrupted by link scanners or cross-device flows.
Biometric authentication
For a mobile app, use platform APIs such as Apple's LocalAuthentication or Android's biometric APIs to unlock a local credential or protect a sensitive action. For website sign-in, use passkeys rather than trying to collect biometric data directly.
Trade-off: a biometric prompt alone doesn't identify an account to your server; you need a trusted authentication mechanism behind it.
Passkeys (WebAuthn)
The server issues a challenge, the device signs it using a private key, and the server verifies the signature using the registered public key. The private key isn't sent to your server.
Trade-off: stronger phishing resistance, but you need correct domain configuration, platform support, and account-recovery flows.
For technical reference, see Google's passkey implementation guide and server-side implementation guide.
A web app or SaaS MVP
Start with Clerk if polished UI and fast integration are priorities. Choose Supabase Auth if your backend already uses Supabase and magic links are your immediate requirement.
Security-first passwordless login
Prioritize passkeys via Clerk, Auth0, or WorkOS AuthKit, verifying that the precise flow you need is supported on your platform. Passkeys are generally preferable to email links as the primary authentication method for phishing resistance.
A native iOS or Android app
Use a provider with a suitable native SDK, or combine your auth provider with Apple's or Android's credential APIs. Decide whether you want device biometrics only for local app unlocking or passkeys for server-verified sign-in.
B2B SaaS with enterprise customers
Compare Auth0 and WorkOS for the broader identity requirements, particularly SSO, organization management, and MFA. WorkOS is particularly relevant if enterprise SSO is on your roadmap.
Whichever provider you choose, verify these capabilities:
I can recommend a specific API and outline the integration. The biggest factor is what you're building.
What platform are you building for?
Web app (React, Next.js, or other)
Native iOS or Android app
Both web and mobile
API or backend only
Which authentication methods do you need?
Magic links only
Passkeys with Face ID or fingerprint
Both magic links and passkeys
Magic links, passkeys, and native biometrics
How much infrastructure do you want to manage?
Managed provider that handles authentication and sessions
Self-hosted or open-source authentication
Custom backend with maximum control
How do you want to build the sign-in UI?
Prebuilt UI components
Custom UI using API endpoints or SDKs
Either is fine
[Compare the best options]
