authentik vs Duo Directory: Side-by-Side Comparison (2026)

Short answer

Startups and SMBs that need SSO and MFA without vendor lock-in should run authentik; the open-source model means you own the codebase, avoid licensing creep as you scale, and can self-host or go hybrid without renegotiating contracts. It covers NIST PR.AA identity management and access control natively, and the built-in application proxy handles remote access to RDP, SSH, and VNC without bolting on a separate tool. Expect to staff more ops lift than a SaaS alternative; this is not the tool for teams wanting a hands-off managed identity service. Mid-market and enterprise teams replacing legacy directory services need Duo Directory for its phishing-resistant MFA and passwordless authentication, which actually reduce the attack surface that traditional password-plus-code approaches leave open. The platform covers NIST PR.AA identity management and access control with automated provisioning across multiple identity sources, eliminating manual sync errors that plague directory deployments. Pass on this if your organization needs deep endpoint detection or network segmentation; Duo Directory is identity infrastructure, not a replacement for EDR or zero-trust network access.