Top 6 Open-Source MFA and Passwordless Tools
The best open-source MFA and passwordless tools in 2026, from Keycloak and Zitadel to Authelia, Hanko, Ory Kratos, and privacyIDEA, covering passkeys, WebAuthn, TOTP, and who each fits.
- Open-source MFA and passwordless tools add multi-factor and passkey authentication without per-user licensing, and let teams self-host the most sensitive part of the login.
- The leading options in 2026 are Keycloak, Zitadel, Authelia, Hanko, Ory Kratos, and privacyIDEA.
- For modern passkeys and WebAuthn, Hanko and Zitadel are the most passwordless-first; Keycloak and Ory are broad identity platforms with strong MFA; Authelia adds 2FA in front of existing apps; and privacyIDEA is the specialist OTP and token server.
Multi-factor authentication is the single highest-impact control against credential theft, and passkeys are steadily replacing passwords with phishing-resistant, passwordless login built on the FIDO2 and WebAuthn standards. Commercial platforms charge per user for these capabilities, which is exactly where open-source tools help: they add MFA, WebAuthn, and passkeys without per-user fees, and let teams self-host the most sensitive part of the login stack. For organizations with the capacity to run them, open-source MFA and passwordless tools deliver strong, standards-based authentication at infrastructure cost.
The options span two shapes. Some are full identity platforms that include MFA and passwordless as part of a broader authentication stack; others are focused tools that add a second factor or passkey experience to systems you already run. This guide evaluates the six open-source MFA and passwordless tools worth knowing in 2026. For the commercial field, see our top passwordless authentication platforms, and for the standard itself, WebAuthn and FIDO2. This is part of our open-source series alongside the top open-source IAM solutions.
Evaluation Criteria
We assessed each tool against the following dimensions:
- Passkey and WebAuthn support, FIDO2 passwordless and phishing-resistant login
- MFA methods, TOTP, HOTP, push, SMS/email, hardware tokens
- Deployment shape, full identity platform vs add-on factor service
- Integration, how it plugs into existing apps and identity
- Developer and admin experience, SDKs, UI, configuration
- Deployment, self-hosting complexity, Docker, Kubernetes, HA
- Community and support, activity, release cadence, commercial options
The Top 6 Open-Source MFA and Passwordless Tools
1. Keycloak
Best For: Teams wanting a full identity platform with configurable MFA and WebAuthn built in.
Overview
Keycloak is the most widely deployed open-source identity platform, and its authentication is highly configurable, including MFA and passwordless. It supports TOTP and HOTP one-time passwords, WebAuthn and passkeys, and recovery codes, and its authentication flows let administrators require step-up factors based on context. Because Keycloak handles the full login, it is the natural choice when you want MFA and passwordless as part of one identity provider rather than a bolt-on. As with any Keycloak deployment, high-scale operation needs tuning, and deep customization can require Java expertise.
Key Features
- WebAuthn and passkey (FIDO2) authentication
- TOTP and HOTP one-time passwords with recovery codes
- Configurable authentication flows with step-up MFA
- Conditional factors based on context and risk
- Broad protocol support and identity brokering
License Apache 2.0. Free to self-host; Red Hat build of Keycloak is a paid subscription.
Pros
- MFA and passwordless within a complete identity platform
- Mature, battle-tested, huge community
- Flexible, context-aware authentication flows
Cons
- High-scale operation requires tuning
- Deep customization can require Java
- Heavier than a focused MFA add-on
2. Zitadel
Best For: Teams wanting a modern, passwordless-first identity platform with native passkeys.
Overview
Zitadel is a modern open-source identity platform built with passwordless in mind, offering native passkey and WebAuthn support alongside TOTP and other factors. Its login experience treats passkeys as a first-class option rather than an afterthought, which suits teams that want to move users off passwords by default. Written in Go and designed for horizontal scale and multi-tenancy, Zitadel is one of the easier modern platforms to operate while still delivering strong, standards-based MFA and passwordless. It is younger than Keycloak, so validate enterprise-specific needs.
Key Features
- Native passkey and WebAuthn support
- Passwordless-first login experience
- TOTP and additional second factors
- Multi-tenancy and organizations
- Self-hosted or Zitadel Cloud
License Apache 2.0. Free to self-host; Zitadel Cloud is a paid managed service.
Pros
- Passkeys and passwordless as first-class options
- Modern, scalable, and easier to operate than many peers
- Multi-tenancy built in
Cons
- Smaller ecosystem than Keycloak
- Younger project, though maturing quickly
- Fewer prebuilt enterprise integrations
3. Authelia
Best For: Self-hosting teams adding two-factor and SSO in front of existing applications.
Overview
Authelia is an open-source authentication and authorization server that provides two-factor authentication and single sign-on through a reverse proxy such as NGINX, Traefik, or Caddy. Rather than replacing an application's identity, it sits in front of web apps and enforces a login and second factor before requests reach them, which makes it popular for securing self-hosted services and homelab-to-enterprise deployments. It supports TOTP and WebAuthn as second factors and push notifications, and it is lightweight to run, though its model is gating access to apps behind a proxy rather than acting as a full identity provider.
Key Features
- Two-factor authentication via reverse proxy
- WebAuthn and TOTP second factors, plus push
- Single sign-on across proxied applications
- Access control rules per application and path
- Lightweight, container-friendly deployment
License Apache 2.0 (true open source).
Pros
- Adds MFA and SSO to apps without modifying them
- Lightweight and simple to deploy
- Good fit for securing self-hosted services
Cons
- Gates access via proxy rather than being a full IdP
- Not a user-management platform on its own
- Best suited to reverse-proxy architectures
4. Hanko
Best For: Developer teams building a passkey-first login into a modern app.
Overview
Hanko is an open-source, passkey-first authentication solution designed to replace passwords with FIDO2 passkeys and email-based flows. It ships prebuilt, embeddable web components so developers can add a passwordless login quickly, along with a backend that manages users and credentials. Hanko is aimed squarely at teams that want a modern, passwordless customer experience without building WebAuthn handling themselves, and it can be self-hosted for full control or used as a managed cloud. As a focused authentication tool it is lighter on broader identity governance than the full platforms.
Key Features
- Passkey-first authentication with FIDO2/WebAuthn
- Prebuilt, embeddable login web components
- Email-based passwordless flows and second factors
- Self-hosted or Hanko Cloud
- Developer-focused APIs and SDKs
License Open-source (AGPL); managed cloud available.
Pros
- Fast path to a passkey-first login
- Embeddable components reduce WebAuthn work
- Self-host for full data control
Cons
- Focused on authentication, lighter on governance
- Younger project and smaller community
- Broad identity needs may outgrow it
5. Ory Kratos
Best For: Engineering teams building custom identity with MFA into modern applications.
Overview
Ory Kratos is the identity and user-management component of the open-source Ory stack, with a headless, API-first design and support for MFA and passwordless flows including WebAuthn, TOTP, and lookup secrets. Because it is headless, teams build their own login and account UI against clean APIs, which gives full control over the authentication experience at the cost of more up-front work. Kratos suits product teams that want passwordless and MFA as part of a composable, cloud-native identity foundation, and it pairs with Ory Hydra for OAuth 2.0 and Ory Keto for permissions.
Key Features
- Headless, API-first identity and user management
- WebAuthn, TOTP, and lookup-secret MFA
- Passwordless and recovery flows
- Cloud-native, horizontally scalable
- Pairs with the broader Ory stack
License Apache 2.0. Free to self-host; Ory Network is a paid managed service.
Pros
- Full control over the authentication experience
- Composable with the rest of the Ory stack
- Modern MFA and passwordless support
Cons
- Headless model means you build the UI
- More up-front engineering than turnkey tools
- Multiple components to operate
6. privacyIDEA
Best For: Teams needing a dedicated OTP and token server that plugs into existing systems.
Overview
privacyIDEA is an open-source multi-factor authentication and token-management server focused on adding a second factor to systems you already run. It manages a wide range of tokens, TOTP and HOTP hardware and software tokens, WebAuthn, SMS and email codes, and paper tokens, and it integrates through RADIUS, PAM, an LDAP proxy, and a REST API, so it can add MFA to VPNs, Linux logins, and web applications without replacing their identity. privacyIDEA is the specialist choice when the requirement is centralized, auditable token and OTP management rather than a full identity platform, and it offers commercial support for production deployments.
Key Features
- Centralized management of many token types
- TOTP, HOTP, WebAuthn, SMS, email, and paper tokens
- Integration via RADIUS, PAM, LDAP proxy, and REST API
- Detailed policies and audit logging
- Adds MFA to existing systems without replacing identity
License AGPL (true open source); commercial support available.
Pros
- Broadest token and OTP coverage of any tool here
- Plugs into existing logins via standard protocols
- Strong policy and audit capabilities
Cons
- A token server, not a full identity platform
- Setup and integration require effort
- UI and experience are utilitarian
How to Choose
For MFA and passwordless as part of a complete identity provider, Keycloak is the safe default and Ory Kratos the headless, API-first alternative. For a passwordless-first experience with native passkeys, Zitadel as a platform and Hanko as a focused, embeddable login lead. Choose Authelia to add two-factor and SSO in front of existing apps behind a reverse proxy, and privacyIDEA when you need a dedicated OTP and token server that plugs into VPNs, Linux logins, and web apps you already run.
The recurring theme in 2026 is passkeys: WebAuthn is now well supported across the open-source options, so moving users off passwords no longer requires a commercial platform. For the commercial field and managed options, see the top passwordless authentication platforms, and for the underlying standard, WebAuthn and FIDO2.
Frequently asked questions
- What are the best open-source MFA and passwordless tools in 2026?
- The top open-source MFA and passwordless tools in 2026 are Keycloak, Zitadel, Authelia, Hanko, Ory Kratos, and privacyIDEA. Hanko and Zitadel are the most passwordless-first with strong passkey support, Keycloak and Ory are broad platforms with capable MFA, Authelia adds two-factor in front of existing apps, and privacyIDEA specializes in OTP and token management.
- Can open-source tools support passkeys and WebAuthn?
- Yes. Keycloak, Zitadel, Hanko, and Ory Kratos all support WebAuthn and passkeys, the FIDO2 standards behind phishing-resistant, passwordless login. Hanko and Zitadel are built passkey-first, while Keycloak and Ory add WebAuthn alongside other factors. See our what-is-passwordless guide for how the standard works.
- What is privacyIDEA?
- privacyIDEA is an open-source multi-factor authentication and token management server. It manages a wide range of second factors, including TOTP and HOTP hardware and software tokens, WebAuthn, and SMS or email codes, and integrates with existing logins through RADIUS, PAM, LDAP proxy, and a REST API. It is the specialist choice when the need is centralized OTP and token management rather than a full identity platform.
- How do you choose an open-source MFA or passwordless tool?
- Match the tool to your need: Keycloak or Ory Kratos for a full identity platform with MFA, Zitadel or Hanko for a passwordless-first, passkey-native experience, Authelia to add two-factor and SSO in front of existing apps behind a reverse proxy, and privacyIDEA when you need a dedicated OTP and token server that plugs into current systems. Confirm your team can operate it before standardizing.