Duo Mobile

Overview

Duo Mobile is a mobile authentication app for approving sign-ins, generating passcodes, and protecting company and personal accounts. It is best suited to organizations securing access across varied apps and infrastructure, rather than people looking only for a standalone personal authenticator. Its combination of broad integration options and adaptive access controls is the main draw, but the organization-led support model is a meaningful trade-off for end users.

Key features

Duo Push lets users approve or deny a login with a tap; time-based passcodes provide a code-entry alternative, and the iOS and Android apps can hold third-party TOTP accounts too. Biometrics, passcodes, and push notifications give organizations multiple authentication methods to support. That flexibility is useful when a push approval is unsuitable, though Duo Mobile's strongest capabilities are tied to organizational deployment rather than a purely personal workflow.

Duo Restore backs up and restores Duo-protected accounts when a user changes Android or iOS devices. Security Checkup sends a security score for the user's mobile device through notifications. These features help with account continuity and device awareness, but enrollment, activation, reactivation, and troubleshooting assistance for end users goes through their organization's Duo administrator.

For IT teams, Duo integrates with legacy infrastructure, major platforms, custom apps, VPNs, SaaS tools, and offline devices. Connections can use RADIUS, SAML/OIDC, Duo Authentication Proxy, or direct API integrations. Adaptive policies can account for user role, location, application, network, and device health, which makes Duo more relevant to teams seeking context-sensitive access than to users who only need codes. Its ecosystem marketplace lists 701 applications. Duo says it uses asymmetric cryptography, keeps private keys on users' devices in a tamper-proof secure element, and does not store passwords.

Pricing

Duo Free costs nothing and covers 10 users. It is a practical starting point for a very small team, but the seat cap makes it a limited fit for broader rollouts.

Duo Essentials costs $3 a month and adds Duo Directory, phishing-resistant MFA, passwordless authentication, SSO, Trusted Endpoints, and unlimited applications. This is the entry paid tier for teams that need passwordless sign-in and wider application coverage. Duo Advantage costs $6 a month and adds Cisco Identity Intelligence, Duo Passport, session theft protection, Active Directory Defense, and risk-based authentication; those protections make it the stronger fit where identity threats and risk-based decisions are priorities. Duo Premier costs $9 a month and adds Zero Trust access, VPN-less remote access, and complete device trust with an endpoint protection check, targeting teams that want those access and device controls together.

A 30-day trial is offered. The paid tiers are differentiated by security and access capabilities, while the free plan is constrained by its 10-user limit; choose the lowest tier that covers the controls your organization needs.

Platforms

Duo Mobile runs on Apple iOS and Google Android phones and tablets, and supports many smart watches. The mobile apps are the basis for push approvals, passcodes, third-party TOTP accounts, and device notifications.

Who it's for

Duo is a strong fit for organizations that need to secure access across mixed infrastructure and apps, especially those that value adaptive policies, directory and SSO capabilities, or phishing-resistant and passwordless methods. Teams can choose among RADIUS, SAML/OIDC, proxy, and API integration paths, and paid plans extend into device trust and Zero Trust access. It is less suitable for an individual who wants only a simple authenticator and expects to manage all account support directly.

Pros and cons

Pro: Push approval, passcodes, biometrics, and third-party TOTP support give users more than one way to complete authentication.

Pro: Integration options cover legacy systems as well as SaaS, VPNs, custom apps, and offline devices, giving administrators flexibility across varied environments.

Pro: Restore, adaptive policies, and multiple paid security tiers extend Duo beyond one-time code generation.

Con: Duo Free is capped at 10 users, so it is not a broad-team tier.

Con: End users needing account setup or troubleshooting help must rely on their organization's Duo administrator.

Con: Its administrative and integration breadth is unnecessary overhead for someone who only needs a personal authenticator.

Alternatives

For a wider comparison, see Multi-Factor Authentication Software, Authenticator apps, Passkey Authentication Software, Passwordless Authentication Software, Identity Threat Detection and Response Software, and Business VPN Software.

Consider cidaas if you need customer or workforce identity tooling across Android, iOS, web, API, and Windows, with a free customer IAM tier for 500 registered users. HYPR Authenticate is an alternative to consider for phishing-resistant onboarding, with a $3 a month entry plan and support for a broader set of platforms including desktop operating systems. FusionAuth is worth considering when a freemium, self-hosted option with unlimited use and core authentication features is the priority. Okta Customer Identity Cloud is another freemium identity option, with an Essentials plan at $35 a month for up to 500 monthly active users and 10 organizations. Authio Lobby may suit projects under 10,000 monthly active users seeking passwordless methods without SSO or SCIM on its free tier. Ory is an alternative identity platform with a developer tier and a Production plan at $770 a year. Supabase may suit projects prioritizing a free backend tier that includes 50,000 monthly active users, 500 MB database per project, 5 GB egress, and 1 GB file storage. Google Cloud Identity is an alternative for teams seeking identity features with automated provisioning and context-aware access on its annual plan at $6 a month.

Verdict

Choose Duo Mobile if your organization needs a mobile authentication layer that can span varied systems and scale from basic approvals to adaptive, device-aware access controls. The combination of integration breadth, account restore, and tiered security capabilities is its strongest reason to choose it. Look elsewhere if you need a standalone personal authenticator or want end users to handle account support without an administrator.