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OpenOTP Authentication Server
What OpenOTP Authentication Server is
OpenOTP Authentication Server is a multi-factor authentication server for protecting network access with one-time passwords (OTP) and FIDO2. It can run on premises or as a cloud/SaaS service, and supports Android, iOS, Linux, macOS, Windows, web and API environments. Authentication options include mobile push, passkeys, FIDO2, YubiKey, OATH tokens, SMS, email, printed OTP lists and PKI certificates. OpenOTP works with local Active Directory and LDAP directories, and lists integrations with Entra ID, DUO, Okta, Google, Ping Identity and One Identity. Administrators can set policies by application, user or group, with risk, network, geolocation and contextual conditions, as well as step-up and step-down authentication. Security features include phishing and denial-of-service protection, geo-fencing, replay attack protection, leaked-password protection and integrated PKI. Federation options include SAML, OpenID Connect, OAuth2 and Kerberos. The product also offers plugins for Windows login, Linux and macOS PAM, macOS login, ADFS, RDWeb Gateway, SimpleSAMLphp and Nextcloud. Its RADIUS Bridge supports VPN and Wi-Fi or NAC authentication. Free options include an on-premise edition for fewer than 25 users and trials for SaaS and on-premise deployments.
Who it suits
OpenOTP suits organizations that need to secure network access across directory-backed users, including SMEs and large corporations in IT, finance, healthcare and government. It can fit teams seeking on-premise or cloud/SaaS deployment, with authentication policies and methods for different access contexts.
What it does well
- Supports passkeys, FIDO2, push, TOTP, SMS and email authentication.
- Offers on-premise and cloud/SaaS deployment.
- Connects with local Active Directory and LDAP directories.
- Includes SAML, OpenID Connect, OAuth2 and Kerberos federation.
- Free on-premise plan covers under 25 users and one server.
What to know first
- On-premise freeware is limited to one server and has no HA.
- SMS authentication requires credits or an external SMS provider.
- LDAP Bridge OTP is marked unsupported in the listed editions.
- SLA and support services are optional.
Limits
On-Premise Freeware is for fewer than 25 users on one server, without high availability, and is renewable every 365 days. SaaS Trial lasts 30 days and allows up to 250 OpenOTP users and 50 SpanKey hosts; On-Premise Trial lasts 30 days, supports up to 10 users and includes two active/active servers. LDAP Bridge OTP is marked unsupported in the listed editions.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Freeware Edition | 25 users · 1 server | On request |
| Enterprise Edition | 250 users | On request |
| Cloud Edition | 250 users | On request |
| On-Premise Freeware | under 25 users · all features · one server · no HA · 365 days, renewable | Free |
| SaaS Trial | 30 days · up to 250 OpenOTP users · 50 SpanKey hosts | Free |
| On-Premise Trial | all features · 2 active/active servers (HA) · 30 days · up to 10 users | Free |
| OpenOTP On-Premise Edition | Request a quote | On request |
As rcdevs.com lists them, read 20 Sept 2026. The maker's own page has the final word.
Getting started
- Visit the OpenOTP product website.
- Choose on-premise installation or the cloud/SaaS service.
- For on-premise use under 25 users, select On-Premise Freeware; for a trial, choose SaaS Trial or On-Premise Trial.
- Connect local Active Directory or LDAP directories, or configure a listed integration.
- Select authentication methods and access policies for your applications, users or groups.
Verdict
Choose OpenOTP if you need MFA for network access with a choice of deployment, authentication methods and directory integrations. Its free on-premise option is for fewer than 25 users on one server; teams needing high availability or supported LDAP Bridge OTP should review the edition limits.
Questions
Is OpenOTP free?
Yes. On-Premise Freeware costs nothing for fewer than 25 users on one server. SaaS and on-premise trial plans are also listed as free.
What platforms does OpenOTP support?
Listed platforms are Android, API, iOS, Linux, macOS, self-hosted, web and Windows.
Can OpenOTP be self-hosted?
Yes. It is offered for on-premise installation as well as as a cloud/SaaS service.
Which authentication methods does it offer?
Listed options include mobile push, FIDO2 and passkeys, YubiKey, OATH tokens, SMS, email, printed OTP lists and PKI certificate authentication.
Which directories and integrations does OpenOTP support?
It supports local Active Directory and LDAP directories, and lists Entra ID, DUO, Okta, Google, Ping Identity and One Identity integrations.
Does OpenOTP include support services?
SLA and support services are optional. RCDevs links to product documentation and community forums.
Facts from OpenOTP Authentication Server's own pages
- Access policies
- The feature list includes per-application, per-user and group, risk-based, network and geolocation policies, plus contextual authentication and step-up/step-down policies. · rcdevs.com, 30 Sept 2026
- Authentication methods
- Listed methods include mobile push, FIDO2/passkeys, YubiKey, OATH tokens, SMS, email, printed OTP lists, and PKI certificate authentication. · rcdevs.com, 30 Sept 2026
- Deployment
- OpenOTP is offered for on-premise installation and as a cloud/SaaS service. · rcdevs.com, 30 Sept 2026
- Directory integration
- The product supports local Active Directory and LDAP directories and lists integrations with Entra ID, DUO, Okta, Google, Ping Identity, and One Identity. · rcdevs.com, 30 Sept 2026
- Federation and API
- Listed integration features include SAML, OpenID Connect, OAuth2, Kerberos, an ADFS plugin, Windows login plugin, RPC-based management API, and SIEM integration. · rcdevs.com, 30 Sept 2026
- Free plan
- Yes · rcdevs.com, 20 Sept 2026
- Headquarters
- Esch-sur-Alzette, Luxembourg · rcdevs.com, 28 Sept 2026
- Intended customers
- RCDevs says it serves SMEs and large corporations across IT, finance, healthcare, and government sectors. · rcdevs.com, 30 Sept 2026
- Legacy LDAP applications
- The optional OpenOTP LDAP Bridge acts as a proxy to provide OTP login mechanisms for existing LDAP users and legacy applications. · rcdevs.com, 30 Sept 2026
- Notable limits
- The feature table marks LDAP Bridge OTP as currently unsupported in the listed editions and says SMS authentication requires SMS credits or an external SMS provider. · rcdevs.com, 30 Sept 2026
- Platform plugins
- RCDevs lists OpenOTP plugins for Windows login, Linux PAM, macOS PAM and login, ADFS, RDWeb Gateway, SimpleSAMLphp, and Nextcloud. · rcdevs.com, 30 Sept 2026
- Purpose
- OpenOTP is an MFA server with OTP and FIDO2 for securing user network access. · rcdevs.com, 30 Sept 2026
- Security features
- The feature list includes phishing protection, denial-of-service protection, intelligent geo-fencing, replay attack protection, leaked-password protection, and integrated PKI. · rcdevs.com, 30 Sept 2026
- Support
- The feature table lists SLA and support services as optional, and RCDevs links to product documentation and community forums. · rcdevs.com, 30 Sept 2026
- VPN and RADIUS
- The OpenOTP RADIUS Bridge provides a RADIUS API over OpenOTP web services and supports enterprise VPN appliances and EAP for Wi-Fi or NAC authentication. · rcdevs.com, 30 Sept 2026
Where OpenOTP Authentication Server stands on Freedom251
- Authenticator apps#20 of 111
- Multi-Factor Authentication APIs#9 of 25