LinOTP

LinOTP is open-source software for multi-factor authentication, aimed at organizations managing identity and access across a mix of users and applications. It is most compelling for teams prepared to run their own authentication infrastructure; those wanting installation flexibility across Linux distributions should verify their deployment path before committing.

Overview

Developed and maintained by netgo software GmbH, LinOTP is positioned for installations ranging from small environments to enterprises with thousands of users, including distributed setups. Its combination of authentication methods, directory connections, and integration protocols can make it a practical choice for organizations that need MFA to span different systems rather than one narrow access route.

The open-source architecture is auditable, and LinOTP describes its signed audit log as tamper-proof, recording authentication and management actions. The product also cites support for requirements associated with GDPR, ISO 27001, NIS2, BSI IT-Grundschutz, PSD2, and PCI-DSS. Those capabilities are relevant to organizations with formal security obligations, though they do not replace assessing a specific deployment against those obligations.

Key features

Authentication options and integrations

LinOTP supports HOTP, TOTP, mOTP, OCRA, SMS and email OTP, push, QR, YubiKey, FIDO U2F, WebAuthn, RADIUS, remote and forwarding options, static passwords, and daily passwords. This range can accommodate different users and systems, but it also leaves administrators with a broad set of factors and policies to manage.

Integration routes include HTTP/JSON API, PAM, RADIUS, SAML, OpenVPN, SSH, Apache, and WordPress. The product page also names SAML, OIDC, ADFS, and RADIUS among its protocols. Connections to Active Directory, LDAP, and SQL databases—including PostgreSQL, MySQL, MariaDB, Oracle, and DB2—make it relevant to organizations with established directories or database-backed identity data.

Self-service and offline access

Users can register, manage, and reset their tokens through a self-service portal, reducing the need for administrators to handle each routine token change. Hardware tokens can be automatically resynchronized. LinOTP also describes offline authentication for Windows users without a permanent internet connection, which suits environments where connectivity cannot be assumed.

Deployment and installation

Deployment choices include a virtual appliance compatible with common hypervisors and containers for Kubernetes and other orchestration platforms. The Linux installation path deserves attention: LinOTP 3 packages are listed for Debian 10 Buster, RPM packages are currently available only for LinOTP 2, and other distributions may require source or pip installation. Organizations standardizing on a different distribution should confirm that this path fits their operational practices.

Pricing

LinOTP's pricing model is free, and the open-source software plan costs nothing under AGPLv3 and GPLv2. The demo license is also free, but it is a test deployment arranged by request with the LinOTP team rather than an automatically provisioned trial.

Paid support offerings include SLA-backed support contracts, software subscriptions, integration services, possible 24/7 emergency response, SaaS, training, and remote or on-site help. These are options for organizations that need vendor assistance or a hosted service; the open-source plan is the fit for teams able to manage deployment and ongoing operations themselves.

Platforms

LinOTP supports Android, iOS, Linux, Windows, web, API, and self-hosted environments. Its virtual appliance and container options add deployment flexibility, while the package limitations for LinOTP 3 may make some Linux environments less straightforward than others.

Who it's for

LinOTP suits organizations that want control over MFA infrastructure, need several authentication factors, and already rely on directory, database, or application integrations. Its scale claims and distributed deployment support make it relevant beyond small installations, while self-service token management can reduce routine administrative work.

It is less suitable for teams seeking a turnkey Linux installation on any distribution or those that do not want responsibility for operating authentication services. Those organizations should weigh the installation path and the paid support options against their staffing and deployment requirements.

Pros and cons

• Pros: Broad factor support, including push, QR, SMS, email, hardware tokens, and WebAuthn, gives organizations options for varied user and system needs.
• Pros: Directory and database connections, plus application integration routes such as PAM, SSH, OpenVPN, and WordPress, support use across a mixed environment.
• Pros: Self-service token management and offline Windows authentication address routine enrollment needs and disconnected access scenarios.
• Pros: Free open-source licensing and virtual appliance or container deployment let capable teams choose how to operate the platform.
• Cons: LinOTP 3's Debian 10 package availability and the narrower RPM support for LinOTP 2 may complicate adoption on other Linux distributions.
• Cons: Organizations needing SLAs, integration help, or emergency response must consider paid support offerings.

Alternatives

• Protectimus MFA is worth comparing for teams looking for a paid MFA option with a free plan and a stated individual price of $2 a month.
• LoginTC offers a Cloud Starter free plan for up to 3 users, making it a candidate for very small teams evaluating hosted MFA.
• miniOrange Multi-Factor Authentication has a free plan starting at $0 per month for individuals just getting started, which may suit an individual-first evaluation.
• Spriv Adaptive MFA has a free Startup plan for up to 2 users and 2 servers, with SMS billed at carrier cost; it is a fit for a small initial deployment.
• Duo Mobile has a free plan for 10 users and may suit a small group comparing mobile-focused MFA.
• HYPR Authenticate is a paid alternative with a stated monthly plan for web access and phishing-resistant onboarding.
• Deepnet DualShield MFA Platform is an on-premises or private-cloud option for organizations that prefer to request a quote.
• Imprivata Enterprise Access Management uses modular licensing, with Core Access required for all deployments and add-on modules varying by workflow.

Browse more options in Multi-Factor Authentication Software.

Verdict

Choose LinOTP if your organization wants free, auditable MFA software with varied factors, directory connections, self-service token administration, and control over deployment. Look elsewhere if your Linux environment does not align with its package options or if you need a turnkey service and do not want to operate authentication infrastructure.