Auth0

Auth0 is a cloud-based identity and access management platform in the Security & Access category that provides authentication, authorization, and user management for web, mobile, and API applications, with a free tier supporting up to 25,000 monthly active users and paid plans starting at $35 per month.

Auth0 handles the full spectrum of identity workflows so development teams can ship secure login, signup, and session management without building authentication infrastructure from scratch. It supports OAuth 2.0, OpenID Connect, SAML 2.0, and WS-Federation out of the box, letting applications connect to social providers (Google, Apple, Facebook, GitHub, and more), enterprise identity providers via SAML or OIDC federation, and traditional username-password databases with configurable password policies.

The platform's Universal Login provides a centralized, customizable authentication page that works across all of a tenant's applications, supporting branding, localization, and progressive profiling. Multi-factor authentication options include TOTP apps, SMS, email OTP, push notifications via the Guardian app, and WebAuthn-based passkeys for phishing-resistant biometric and hardware key login.

Auth0's Actions engine allows developers to inject custom Node.js logic at specific points in the authentication pipeline — post-login, pre-registration, post-password change, and during credential exchange — enabling use cases like enriching tokens with external data, enforcing custom business rules, or triggering downstream webhooks. This replaces the older Rules and Hooks system with a more composable, debuggable extensibility model.

For B2B SaaS builders, Auth0's Organizations feature provides multi-tenant identity management with per-customer SSO configuration, member invitation flows, and organization-scoped RBAC. Each organization can have its own enterprise connection, branding, and MFA policy, making it straightforward to sell into enterprises that require federated identity.

Auth0 includes built-in attack protection covering brute-force detection, suspicious IP throttling, breached password detection, and bot mitigation. Tenant log streams can forward authentication events to Datadog, Splunk, Sumo Logic, Amazon EventBridge, and other observability platforms for real-time monitoring and compliance auditing.

The Auth for GenAI initiative extends Auth0 into agentic AI workflows. It provides patterns, SDKs, and integration guidance for authenticating AI agents that act on behalf of users, including scoped token issuance, async human-in-the-loop authorization for sensitive actions, and secure tool-calling with third-party APIs. This positions Auth0 as one of the few identity providers actively addressing the emerging challenge of machine-to-machine and agent-to-API identity.

Auth0 holds SOC 2 Type II, HIPAA, PCI DSS, and ISO 27001 compliance certifications. Data residency options are available in the US, EU, and Australia. The platform processes over 4.5 billion authentication transactions per month across more than 18,000 customers globally, with a 99.99% uptime SLA available on Enterprise plans.

Developers can manage Auth0 tenants programmatically through the Management API, Terraform provider, and Deploy CLI, enabling infrastructure-as-code workflows. SDKs and quickstart guides are available for React, Next.js, Angular, Vue, Express, Django, Rails, Spring Boot, iOS, Android, Flutter, and more than 30 additional frameworks.

Auth0 is part of Okta's Customer Identity Cloud, distinct from Okta's Workforce Identity product. While Okta Workforce targets IT administrators securing employee access to internal apps, Auth0 is developer-focused and optimized for customer-facing identity in SaaS, e-commerce, healthcare, fintech, and media applications.