Best Free Auth Tools

Fine-grained authorization as a service for applications and APIs. Free up to 1000 MAUs and 100 authorizer instances.

Developer authentication via Auth0 platform — 25,000 MAU free, social login, passwordless, MFA, SSO. Note: developer.okta.com/signup now routes to Auth0.

A turnkey user and access management that works for you and supports multi-tenant (B2B) use cases. Free for up to 100 Daily Active Users, with all security features (no paywall for OTP, Passwordless, Policies, and so on).

Bring Passwordless, OTPs, 2FA, SSO to your apps in minutes. All Front-end included. Free tier: unlimited MAUs, up to 2 applications, 100 SMS/month. Best for unlimited usage needs.

Superseded: As of 2026-09-10, authress.io reads: First 1000 billable calls are free. 0.0012 USD per call, billed monthly. We are not publishing our stored Authress terms beside it — our own pricing change record, discovered 2026-09-10, names them as the previous ones. Read what we recorded ↓ Note — discovered 2026-09-10: The first 1000 billable calls are free, and after that, pricing is 0.0012 USD per call. Source ↗

Authentication for B2B SaaS — free up to 10,000 MAUs and 10K Transactional Emails (with a watermark branding: "Powered by PropelAuth").

A complete authorization management system for authoring, testing, and deploying access policies. Fine-grained authorization and access control, free up to 100 monthly active principals.

Two-factor authentication (2FA) on multiple devices, with backups. Drop-in replacement for Google Authenticator. Free for up to 100 successful authentications.

Superseded: As of 2026-08-28, permit.io/pricing reads: Community: Free Forever, 1000 MAU, 20 Tenants, No Limit Authorization Queries, 25 Roles, 50 Resource Types, 5 Role Assignments, 2,000 Groups, 2,000 Resource Instances, 2,000 Relationship Tuples. Free for OSS Projects - Contact Us. We are not publishing our stored Permit.io terms beside it — our own pricing change record, discovered 2026-08-28, names them as the previous ones. Read what we recorded ↓ Note — discovered 2026-08-28: The free tier now has limits of 1000 MAU, 20 Tenants, No Limit Authorization Queries, 25 Roles, 50 Resource Types, 5 Role Assignments, 2,000 Groups, 2,000 Resource Instances, 2,000 Relationship Tuples. There is also a free tier for OSS projects, requiring contact for qualification. Source ↗

10,500 MAU, OAuth 2.0/OIDC/SAML, MFA (email/SMS/app), passwordless, multi-tenancy (5 organizations), feature flags (10 max). No credit card required

Self-hosted identity provider covering SSO, SAML, OAuth2/OIDC and LDAP. The open-source edition is free and aimed at homelab users and simple use cases. Enterprise is $5/user/month billed annually with external users at $0.02/user/month and no charge for service accounts; Enterprise Plus starts at $20k annually.

Superseded: As of 2026-09-01, fusionauth.io/pricing reads: Community: 1,000 MAUs Self-hosted: Free Download FusionAuth Community is free and unlimited. It has the core authentication features. Core authentication standards & features most apps need Community support (forums, Slack, Github) Self-host FusionAuth on your own infrastructure for free. We are not publishing our stored FusionAuth terms beside it — our own pricing change record, discovered 2026-09-01, names them as the previous ones. Read what we recorded ↓ Note — discovered 2026-09-01: The Community tier is still offered. It now has a limit of 1,000 monthly active users. Source ↗

Keycloak Identity and Access Management as a Service. Free up to 100 users and one realm.

Superseded: As of 2026-09-02, logto.io/pricing reads: Free tier is $0/month for up to 50,000 MAU and 50K tokens. Includes user authentication, machine-to-machine apps, account APIs, audit logs, and user management. Additional features like RBAC, MFA, and Organizations are paid add-ons. We are not publishing our stored Logto terms beside it — our own pricing change record, discovered 2026-09-02, names them as the previous ones. Read what we recorded ↓ Note — discovered 2026-09-02: The free tier now includes 50K tokens, and many features are add-ons (RBAC, MFA, Organizations) that were previously. Source ↗

AuthKit with up to 1M MAU free for user management — email/password, social login, MFA. Enterprise SSO/SCIM priced separately

Identity platform — 25K MAU (B2C), unlimited logins, social + database connections, Universal Login, 1 Enterprise Connection, 5 Organizations, 1 Custom Domain. No credit card required Best for unlimited usage needs.

Two-factor authentication (2FA) for website or app. Free for ten users, all authentication methods, unlimited, integrations, hardware tokens. Best for unlimited usage needs.

Two-factor authentication (2FA) by push notifications, free for 3 users, VPN, Websites, and SSH

Keycloak Open Source Identity and Access Management. Free Starter realm up to 100 users. SSO connections require paid Premium tier ($749/month). Leveraging Phase Two's enhanced Keycloak container with Organization extension. Best for open source projects. Note — 2026-04-12: Free tier significantly reduced: users from 1,000 to 100, SSO connections from 10 to 0 (now requires paid Premium tier) Source ↗

Now Hexclave — stack-auth.com redirects to hexclave.com, and the GitHub org stack-auth/stack-auth redirects to hexclave/hexclave (same repository). Open-source user infrastructure: auth, teams, RBAC, API keys, emails. Free tier is $0 forever: up to 10,000 auth users, 1 dashboard admin, 1,000 emails per month, email/OAuth/magic links, community support. Also self-hostable for free.

Authentication and user management. Free Forever plan: 7,500 MAU, 10 tenants, 3 SSO connections. All core auth methods: passwords, magic links, OTP, passkeys, social login, MFA

Authentication and fraud prevention — 10,000 MAU, passwordless login, OAuth, MFA, session management, device fingerprinting, 5 SSO/SCIM connections, 1,000 M2M tokens, password breach detection

Open source authentication — cloud: 5K MAUs free. Self-hosted: unlimited. Email/password, social login, passwordless, RBAC, user management dashboard Best for open source projects and unlimited usage needs.

Passkey-first authentication. Cloud free tier: 10,000 MAU, 2 production projects. Also open source (AGPL v3) for unlimited self-hosted use. WebAuthn, OAuth, email/password Best for open source projects and unlimited usage needs.

Free OSS (Apache 2.0). Red Hat-backed identity and access management. SSO, OIDC, SAML, LDAP, social login, MFA, fine-grained authorization. Self-hosted with no user limits Best for open source projects.

Seamless Integration of SSO, MFA, passwordless auth and more. Includes SDKs for frontend and backend apps. Free tier: 7,500 Consumer MAUs (B2C), 250 B2B MAUs, 2 social login providers.

Drop-in auth with 50K monthly retained users free, unlimited apps Best for unlimited usage needs.

Open-source identity infrastructure — Kratos (identity), Hydra (OAuth2/OIDC), Oathkeeper (API gateway), Keto (permissions). Cloud: 25K MAU free. Self-hosted: unlimited, Apache 2.0 Best for unlimited usage needs.

A free tool to search a username across 150+ social platforms to find matching profiles. Best for open source projects.

MojoAuth makes it easy to implement Passwordless authentication on your web, mobile, or any application in minutes.