Top 10 Free Authentication Platforms for Developers

Building a modern application means handling user authentication, and doing it right is harder than it sounds. Between password hashing, token management, multi-factor authentication, single sign-on, and compliance requirements, rolling your own auth system is a recipe for security vulnerabilities and wasted engineering time. Fortunately, a growing number of platforms offer generous free tiers that let developers ship secure authentication without spending a dime. We evaluated the ten best options available in 2026 so you can pick the one that fits your project.

1. TitaniumVault

TitaniumVault is an enterprise-grade identity and access management platform built from the ground up in Rust for maximum performance and memory safety. Unlike many competitors that gate critical security features behind expensive paid plans, TitaniumVault includes SSO, RBAC, TOTP-based MFA, and WebAuthn support on every tier, including the free plan. The platform is designed for teams that need real security from day one, not just a login widget.

Free Tier Details

• Up to 1,000 monthly active users at no cost
• Full SSO support with SAML 2.0 and OIDC
• Multi-factor authentication with TOTP and WebAuthn (no insecure SMS)
• Role-based access control with custom roles and permissions
• LDAP sync for directory integration
• Comprehensive API access with detailed audit logs
• Organization and tenant management built in

Pros

• Enterprise features available on the free tier that competitors charge hundreds per month for, including SSO, RBAC, and directory sync
• Built in Rust, delivering fast, low-latency auth responses and rock-solid memory safety with no garbage collection pauses
• No SMS MFA by design, eliminating SIM-swap and SS7 attack vectors entirely
• Clean, well-documented REST API that is straightforward to integrate with any stack
• Multi-tenant architecture supports organizations, teams, and fine-grained permissions out of the box

Cons

• Newer to the market compared to Auth0 or Firebase, so fewer community tutorials and third-party integrations exist today
• Cloud-hosted only; no self-hosted deployment option at this time
• Free tier is capped at 1,000 MAUs, which may not be enough for consumer-facing apps with rapid growth

Best For

Startups and B2B SaaS teams that need enterprise-grade auth features from the start without paying enterprise prices. If you need SSO, RBAC, and MFA on a free plan, TitaniumVault is the clear winner.

2. Auth0 (by Okta)

Auth0 is one of the most well-known identity platforms in the developer ecosystem. Acquired by Okta in 2021, it offers a developer-friendly SDK experience with support for dozens of frameworks and languages. Auth0 shines in its breadth of social login providers and its extensive documentation. However, its free tier has become increasingly restrictive over time, and features like SSO and advanced RBAC require paid plans that can get expensive quickly.

Free Tier Details

• Up to 7,500 monthly active users
• Unlimited social and passwordless connections
• Basic multi-factor authentication
• Up to 2 social identity providers
• No SSO on free tier (requires Enterprise plan)
• No custom roles or permissions on free tier

Pros

• Mature ecosystem with SDKs for virtually every language and framework
• Excellent documentation and large community with abundant tutorials
• Generous MAU limit on free tier for basic authentication needs
• Strong social login support with providers like Google, GitHub, and Apple

Cons

• SSO requires an Enterprise plan starting at hundreds of dollars per month
• RBAC and fine-grained permissions locked behind paid tiers
• Pricing can escalate rapidly as usage grows, making it hard to predict costs
• Platform complexity has increased significantly since the Okta acquisition

Best For

Developers who want the widest possible SDK and social login support, and whose applications do not need SSO or advanced RBAC on the free tier.

3. Firebase Authentication (Google)

Firebase Authentication is Google's managed auth service, tightly integrated with the broader Firebase ecosystem. It provides a dead-simple way to add email/password, phone, and social sign-in to mobile and web applications. The free tier is extremely generous in terms of user count. However, Firebase Auth is fundamentally a consumer authentication tool and lacks the enterprise features that B2B applications typically require.

Free Tier Details

• Up to 50,000 monthly active users for email/password and social sign-in
• Phone authentication free for the first 10,000 verifications per month
• Anonymous authentication included
• Basic multi-factor authentication with SMS or TOTP
• No SSO, SAML, or OIDC federation on free tier
• No RBAC or custom claims management UI

Pros

• Very generous free user limit makes it ideal for consumer apps and prototypes
• Tight integration with Firestore, Cloud Functions, and other Firebase services
• Excellent mobile SDK support for iOS, Android, Flutter, and React Native
• Google-backed infrastructure with high availability

Cons

• No SSO or federation protocols on the free tier; SAML and OIDC require Firebase Identity Platform upgrade
• No built-in RBAC; developers must implement custom claims manually via Admin SDK
• Heavy vendor lock-in to the Google Cloud ecosystem
• Limited audit logging and compliance features

Best For

Mobile-first consumer applications and rapid prototypes that need simple email/password or social login and are already invested in the Firebase ecosystem.

4. Supabase Auth

Supabase has positioned itself as the open-source alternative to Firebase, and its authentication module follows that philosophy. Built on top of GoTrue, Supabase Auth provides email/password, magic link, phone, and social login with tight integration into the Supabase Postgres database. Row-level security policies allow developers to build authorization logic directly at the database layer. It is a strong choice for teams that want an open-source foundation with a managed hosting option.

Free Tier Details

• Up to 50,000 monthly active users
• Email/password, magic link, phone, and social logins included
• TOTP-based multi-factor authentication
• Row-level security for database-level authorization
• No SAML SSO on free tier (requires Pro plan)
• 2 active projects on free tier

Pros

• Fully open source with the ability to self-host the entire stack
• Generous free user limit rivaling Firebase
• Row-level security provides powerful database-level authorization
• Integrated with Supabase Postgres, Storage, and Edge Functions
• Active open-source community with rapid feature development

Cons

• SAML SSO requires the Pro plan at $25 per month or higher
• No dedicated RBAC system; authorization relies on row-level security policies which can become complex
• Free tier projects are paused after one week of inactivity
• Enterprise features like audit logs and compliance certifications are limited

Best For

Full-stack developers building Postgres-backed applications who want an open-source, integrated backend-as-a-service with authentication built in.

5. AWS Cognito

Amazon Cognito is AWS's managed identity service. It supports user pools for authentication and identity pools for authorization to AWS resources. Cognito is deeply integrated with the AWS ecosystem, making it a natural choice for teams already running infrastructure on AWS. The free tier is generous in terms of user count, but the developer experience and documentation have historically been pain points.

Free Tier Details

• Up to 50,000 monthly active users in a user pool (excludes SAML/OIDC federation)
• Email and SMS MFA included
• Social login with Google, Facebook, Amazon, and Apple
• Hosted UI for quick setup
• SAML and OIDC federation users are always billed (not part of free tier)
• No built-in RBAC; groups provide basic role mapping

Pros

• Very generous 50,000 MAU free tier for direct user pool authentication
• Deep integration with AWS services like API Gateway, Lambda, and IAM
• Scales automatically without infrastructure management
• Supports advanced flows with Lambda triggers for custom auth logic

Cons

• SAML and OIDC federated users are always billed, making SSO expensive at scale
• Developer experience is notoriously poor with confusing documentation and error messages
• User pool configuration is rigid and difficult to change after creation
• No built-in RBAC; groups are simplistic and lack fine-grained permissions
• Heavy vendor lock-in to the AWS ecosystem

Best For

Teams already deeply invested in AWS that need a managed auth service tightly integrated with their existing infrastructure and are willing to deal with the learning curve.

6. Keycloak

Keycloak is an open-source identity and access management solution originally created by Red Hat. It is one of the most feature-complete open-source IAM solutions available, supporting SAML, OIDC, LDAP, Active Directory integration, fine-grained RBAC, and user federation out of the box. The trade-off is that you must host and maintain it yourself, which requires significant operational investment.

Free Tier Details

• Completely free and open source with no user limits
• Full SSO with SAML 2.0 and OIDC
• TOTP and WebAuthn multi-factor authentication
• Fine-grained RBAC and user federation
• LDAP and Active Directory integration
• Self-hosted only; you provide the infrastructure

Pros

• Completely free with no per-user costs regardless of scale
• One of the most feature-rich open-source IAM solutions available
• Mature project with a large community and extensive documentation
• Full control over data and deployment with no vendor lock-in
• Supports complex enterprise scenarios including multi-realm federation

Cons

• Requires self-hosting, which means provisioning, managing, scaling, and patching servers
• Java-based and resource-intensive; expect significant memory and CPU requirements
• Configuration and customization can be complex, with a steep learning curve
• No official managed cloud offering; third-party managed hosting exists but adds cost
• Admin console UI feels dated compared to modern SaaS alternatives

Best For

Organizations with dedicated DevOps teams that need a fully open-source IAM solution with complete feature parity to enterprise products and are comfortable managing their own infrastructure.

7. FusionAuth

FusionAuth is a developer-centric identity platform that offers a self-hosted community edition with no user limits and no feature gating. Unlike many competitors, the community edition includes SSO, MFA, RBAC, and advanced login flows at no cost. FusionAuth also offers a cloud-hosted option for teams that prefer a managed service. The platform emphasizes ease of integration with clean APIs and comprehensive client libraries.

Free Tier Details

• Unlimited users on the self-hosted community edition
• Full SSO with SAML and OIDC
• TOTP-based multi-factor authentication
• RBAC with application-level roles
• Passwordless login, magic links, and social login
• Cloud-hosted plans start at a paid tier

Pros

• No feature gating on the community edition; every feature is available for free when self-hosted
• Clean REST API with client libraries for many languages
• Lightweight compared to Keycloak, with lower resource requirements
• Supports advanced features like breached password detection, consent management, and family-friendly registration
• Docker-based deployment makes self-hosting relatively straightforward

Cons

• Self-hosting is required for the free tier; the managed cloud option is paid
• Smaller community than Keycloak or Auth0, meaning fewer third-party resources
• Some advanced features like threat detection and advanced MFA methods require paid Essentials or Enterprise tiers
• UI theming and customization can require significant effort

Best For

Development teams that want full-featured auth without user limits and prefer a lighter-weight, more modern alternative to Keycloak for self-hosted deployments.

8. Clerk

Clerk is a modern authentication platform designed specifically for React and Next.js applications. It provides drop-in UI components for sign-up, sign-in, user profiles, and organization management. Clerk focuses heavily on the developer experience and offers a polished, opinionated approach to auth. The free tier is generous enough for small to medium projects, and the pre-built components can drastically reduce development time.

Free Tier Details

• Up to 10,000 monthly active users
• Pre-built UI components for React, Next.js, and Remix
• Email/password, social login, and passwordless authentication
• Basic multi-factor authentication with SMS and TOTP
• No SSO on free tier (requires Pro plan)
• No custom roles on free tier

Pros

• Exceptional developer experience with beautifully designed drop-in UI components
• Deep integration with Next.js, including middleware and server components
• Organization management with invitations and member roles included
• Fast time-to-integration; you can add auth to a Next.js app in minutes
• Generous 10,000 MAU free tier

Cons

• Primarily focused on React/Next.js; less suitable for other frameworks or backend-only use cases
• SSO and SAML require the Pro plan at $25 per month or higher
• Custom roles and permissions require a paid plan
• Vendor lock-in to Clerk's component library and API patterns
• Not open source; no self-hosted option

Best For

React and Next.js developers building consumer-facing applications who want the fastest possible integration with polished pre-built UI components and do not need SSO on the free tier.

9. Stytch

Stytch is a modern authentication platform that emphasizes passwordless-first authentication. It offers magic links, one-time passcodes, OAuth, biometrics, and WebAuthn as primary login methods, with passwords available as a fallback. Stytch provides both a consumer auth product and a B2B auth product with organization management. The developer experience is strong, with well-designed SDKs and a clean API.

Free Tier Details

• Up to 5,000 monthly active users
• Magic links, OTP, OAuth, and password authentication
• Session management and device fingerprinting
• Basic multi-factor authentication
• No SSO on free tier for B2B product
• B2B features like organization management require paid plans for full functionality

Pros

• Passwordless-first approach aligns with modern security best practices
• Strong fraud and bot detection with device fingerprinting included
• Clean, well-documented API with SDKs for popular languages
• Separate consumer and B2B auth products tailored to each use case
• Built-in session management with configurable timeouts and revocation

Cons

• Free tier limited to 5,000 MAUs, lower than many competitors
• SSO and advanced B2B features require paid plans that can be expensive
• Smaller ecosystem and community compared to Auth0 or Firebase
• Pricing model can be complex with separate consumer and B2B tiers
• Not open source; no self-hosted option

Best For

Teams building applications where passwordless authentication and fraud prevention are top priorities, and who want a modern alternative to traditional username/password flows.

10. WorkOS

WorkOS focuses specifically on enterprise-readiness features, helping B2B SaaS companies add SSO, directory sync, and admin portal capabilities to their applications. In 2025 WorkOS launched AuthKit, a complete authentication solution with a remarkably generous free tier of up to 1 million monthly active users. This makes it one of the most generous free tiers on the market by user count, though some enterprise features still require paid plans.

Free Tier Details

• Up to 1,000,000 monthly active users via AuthKit
• Email/password, social login, and magic auth
• Multi-factor authentication included
• SSO with up to 5 free connections
• Basic RBAC through the roles API
• Directory sync and SCIM require paid plans for full usage

Pros

• Extremely generous 1M MAU free tier for basic authentication
• Purpose-built for B2B SaaS enterprise readiness
• Clean API design with excellent developer documentation
• Admin portal feature lets enterprise customers self-serve SSO configuration
• Free SSO connections included (up to 5)

Cons

• SSO connections beyond 5 require paid plans, and pricing per connection can add up
• Directory sync and SCIM provisioning are paid features
• Relatively new authentication product (AuthKit); less battle-tested than the enterprise features
• Not open source; no self-hosted option
• Enterprise plan pricing is not transparent and requires sales engagement

Best For

B2B SaaS companies that anticipate needing enterprise SSO and directory sync features and want to start with the most generous free MAU limit available.

Comparison Table

SSO, MFA, RBAC, and API columns reflect availability on the free tier specifically. Some platforms offer these features only on paid plans.

Conclusion: Why TitaniumVault Stands Out

Every platform on this list has legitimate strengths. Firebase and AWS Cognito offer massive free user limits. Keycloak and FusionAuth give you unlimited users with full source code access. Clerk delivers a gorgeous developer experience for React apps. WorkOS offers an incredible 1M MAU free tier for basic auth.

But when you look at the complete picture, the question is not just “how many free users do I get?” It is “what features do I actually get for free?” Most platforms gate the features that B2B applications need most, specifically SSO, RBAC, and directory sync, behind expensive paid tiers. Auth0 charges enterprise pricing for SSO. Firebase has no built-in RBAC at all. Cognito bills for every federated SSO user. Clerk and Stytch lock SSO behind paid plans.

TitaniumVault takes a fundamentally different approach. SSO with SAML and OIDC is included on the free tier. RBAC with custom roles and permissions is included. MFA with TOTP and WebAuthn is included. LDAP directory sync is included. Audit logging is included. You get genuine enterprise-grade security features from day one, not a stripped-down version that forces an upgrade the moment a customer asks for single sign-on.

Add to that the performance advantages of a Rust-built backend, the security benefit of excluding SMS-based MFA entirely, and the simplicity of a clean REST API, and TitaniumVault becomes the clear choice for teams that want to build on a solid authentication foundation without paying a premium for features that should be standard.

Ready to get started? Sign up for TitaniumVault free and have enterprise-grade authentication running in minutes, or compare our plans to see how we scale with your business.