# Secure authentication solutions built for the next generation of apps

Move past standard login screens. Build identity experiences that drive conversion across web, mobile, and agentic apps.

## Build identity your way: hosted, API-based, or both

### Universal Login

Hosted authentication that’s built for more secure handoffs across apps and AI-powered experiences. Deploy custom identity flows fast with streamlined pro-code setup and full design control via [Advanced Customizations for Universal Login (ACUL)](/content/docs/customize/login-pages/advanced-customizations/index.html).

### Embedded Login

API-based authentication that’s built for in-app identity flows. Use Auth0 APIs, SDKs, and components for complete pro-code control. Embed directly into first-party apps across checkout, AI agents, and inline in-app experiences—without redirects or web views.

## Drive higher conversions with secure login experiences

- **Passwordless**: Free your users from passwords with flexible passwordless login options. Give them a choice and offer multiple password-free options on the same connection with no extra setup—such as social login, passkeys, email, or phone one-time passwords (OTPs).

- **Single sign-on**: Log in once. Deliver a frictionless experience that users can access across all your apps — no repeated authentication required.

### Adaptive MFA

The right balance of secure access and effortless user experiences. Risk-based, context-aware authentication enforces additional verification only when needed, without disrupting trusted users or AI-powered workflows.  
[Check out Adaptive MFA](/content/docs/secure/multi-factor-authentication/adaptive-mfa/index.html)

### Multiple identities, one login

From social media and enterprise to legal digital profiles, users juggle numerous online identities. Empower them to consolidate these personas and engage with your apps in a more secure manner.  
[Identity providers](/content/docs/authenticate/identity-providers/index.html)

### Social logins support

Accelerate the registration and authentication process with over 40 social login alternatives available. Easily create your own social login extension to perfectly fit your needs.  
[Social Identity](/content/docs/authenticate/identity-providers/social-identity-providers/index.html)

## Frequently asked questions

### What is Auth0 Authentication?

Auth0 Authentication is a flexible, developer-centric service that [supports a wide range of login methods](/content/docs/authenticate/login/index.html), including username/password, social IDs, [enterprise SSO](/content/docs/authenticate/single-sign-on/index.html), email/sms passwordless, biometrics via [WebAuthN](/content/docs/authenticate/login/auth0-universal-login/passwordless-login/webauthn-device-biometrics/index.html) and [Passkeys](/content/docs/authenticate/database-connections/passkeys/index.html).

### What is 'Step-up' authentication in Auth0?

Step-up authentication is a security pattern where Auth0 challenges a user for an additional factor (like [MFA](/content/docs/secure/multi-factor-authentication/index.html)) only when they attempt a sensitive action, such as changing a password or making a large purchase.

### How does Auth0 handle cross-platform login?

Auth0 provides a unified authentication experience across web, mobile, and desktop applications. By using standardized JWTs (JSON Web Tokens), Auth0 verifies that a user's identity is recognized seamlessly as they move between different platforms in your ecosystem, maintaining a more secure session.

### Can I customize the Auth0 authentication pipeline?

Yes, the Auth0 authentication pipeline is highly extensible via [Auth0 Actions](/content/docs/customize/actions/actions-overview/index.html). Developers can write serverless functions to trigger custom logic during the login process.

### Does Auth0 support biometric authentication?

Yes, Auth0 supports biometric authentication through WebAuthn and [Passkeys](/content/docs/authenticate/database-connections/passkeys/index.html).

### What is the difference between Universal Login and Embedded Login?

Universal Login and Embedded Login are two key ways to build conversion-friendly identity journeys. Many customers use a hybrid approach, using different solutions for different identity patterns.