Best Open Source Alternatives to Duo Security

Compare the best free and open-source alternatives to Duo Security — self-hosted and desktop replacements you fully control, ranked by GitHub stars, license and platform support.

Curated by open-source.store · Updated November 2026 · 3 alternatives

Duo Security

Proprietary SaaS

PricingFreemium

Platformsios, android, web

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Duo Security alternatives compared

Open-source alternatives to Duo Security, compared by stars, license and platform
Tool		License	Platforms	Self-hosted
Ente Auth	29,840	AGPL-3.0	iosandroidWeb	No	Nov 2026	Visit
Aegis Authenticator	13,448	GPL-3.0	android	No	Sep 2026	Visit
PrivacyIdea	1,790	AGPL-3.0	LinuxDocker	Yes	Nov 2026	Visit

Top open-source Duo Security alternatives

Ente Auth29,840AGPL-3.0

Open-source, end-to-end encrypted 2FA authenticator replacing Authy with multi-device sync, audited cryptography, and cross-platform desktop clients.

iosandroidWeb

vs Duo Security: a free, open-source option you fully control, licensed AGPL-3.0.

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Aegis Authenticator13,448GPL-3.0

Aegis Authenticator is an open-source Android 2FA app that replaces Authy with encrypted local vaults, biometric unlock, and offline backup control.

android

vs Duo Security: a free, open-source option you fully control, licensed GPL-3.0.

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PrivacyIdea1,790AGPL-3.0

PrivacyIdea is an open-source, self-hosted multi-factor authentication server that replaces Duo Security with full control over token seeds and user data.

LinuxDocker

vs Duo Security: a free, open-source option you fully control, licensed AGPL-3.0.

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Best Open Source Alternatives to Duo Security

Duo Security

Duo Security alternatives compared

Top open-source Duo Security alternatives

The modern standard for Protobuf workflows

Mentoring for backend developers. Consulting for startups.