# duo

Source: https://startwithidentity.com/vendors/mfa/duo/
Last updated: 2026-09-20
License: content by Start with Identity. Cite the source URL.

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## Overview

Duo is the most straightforward way to buy strong authentication, and one of very few identity products with honest public pricing: [0, 3, 6 and 9 dollars](https://duo.com/pricing) per user per month across Free, Essentials, Advantage and Premier. Cisco [completed its acquisition](https://investor.cisco.com/news/news-details/2018/Cisco-Completes-Acquisition-of-Duo-Security/default.aspx) on 1 October 2018 for 2.35 billion dollars, and Duo remains the shipping brand in 2026 with active releases. Cisco reports 100,000 customers and more than 1.3 billion monthly authentications.

Cisco Identity Intelligence has been folded into Duo rather than replacing it: it is included in Advantage and Premier, requires one of those plans, and since 29 September 2025 is the only user threat detection option offered to new customers.

## What it is good at

Deployment speed and breadth of authentication methods. Duo Push, passkeys and WebAuthn platform authenticators, roaming security keys, hardware HOTP tokens, phone call, SMS and bypass codes are all supported, and the integration catalogue covers effectively every common application. Essentials already includes SSO, Duo Directory, phishing-resistant MFA, full passwordless and Trusted Endpoints, which is more than many competitors put in an entry tier.

The security record is good. The highest-severity Duo CVE between 2024 and 2026 scored 6.2, with no critical or high-severity flaws and none published at all in 2026.

## Where it falls short

Capability gaps are specific rather than general. Duo Passport needs TPM 2.0 or Secure Enclave and has no Linux support. Risk-Based Authentication does not work for Windows Logon or Unix, which undercuts the Advantage tier for on-premises estates. Duo's documentation advises against TOTP hardware tokens because drift and resynchronisation are not fully handled.

Buying through Cisco is where the value can shift. The Secure User Protection Suite included Duo Premier for purchases before 4 December 2024 and Duo Advantage after, per Cisco's own offer terms, and Cisco reserves the right to disable temporarily granted features. Check which entitlement your contract carries.

Duo is also authentication, not identity governance or lifecycle: it does not replace a full IAM platform.

## Pricing

Free, Essentials, Advantage and Premier at 0, 3, 6 and 9 dollars per user per month, per active user, sold in increments of 10 users below 100 and 25 above. Federal editions are unpriced. Compare all-in cost with our [TCO calculator](https://startwithidentity.com/tools/tco-calculator/).

## Best for, and who should look elsewhere

Choose Duo for clear, well-priced MFA and SSO without a full platform commitment. Choose [Microsoft Entra](https://startwithidentity.com/vendors/iam/microsoft-entra/) if MFA is already bundled in your licensing, [Okta](https://startwithidentity.com/vendors/iam/okta/) for broader workforce identity, or [Silverfort](https://startwithidentity.com/vendors/itdr/silverfort/) to reach legacy systems and service accounts Duo cannot. See [Duo vs Microsoft Authenticator](https://startwithidentity.com/compare/duo-vs-microsoft-authenticator/).

## Bottom line

The best-value strong authentication product on the market, with pricing you can actually read, provided the Linux and on-premises gaps do not hit your estate.