Open Source Security & Privacy Tools
A curated collection of the best open source software for protecting systems and data, spanning application and network security, identity and access management, secrets, and threat detection.
Next-Gen CAPTCHA and Spam Protection, GDPR compliant
Stars
2,740Last commit
3 days agoLicense
MIT
ALTCHA offers cutting-edge spam and abuse protection for websites and apps, with privacy-friendly CAPTCHA alternatives designed for GDPR compliance.
Open Source Alternative to:
Serverless team chat over Tor, no phone number needed
Stars
2,646Last commit
13 hours agoLicense
GPL-3.0
Quiet is a peer-to-peer messaging app that syncs messages directly between devices over Tor, with no central server, no phone number required, and no metadata leaks.
Open Source Alternative to:
Secure, private, and decentralized file storage
Stars
2,481Last commit
13 hours agoLicense
AGPL-3.0
A peer-to-peer encrypted filesystem for secure file storage, sharing, and collaboration with end-to-end encryption and user-controlled data.
Open Source Alternative to:
Open-source feature flag management for seamless deployments
Stars
1,906Last commit
20 hours agoLicense
MIT
FeatBit is a fast, scalable feature flag service that enables risk mitigation and fosters business growth through controlled feature releases.
Open Source Alternative to:
Security framework that protects from within your product
Stars
1,507Last commit
26 days agoLicense
AGPL-3.0
Open-source security framework for threat detection, fraud prevention, and abuse monitoring. Self-hosted solution with built-in dashboard and risk scoring.
Open Source Alternative to:
Managed identity and access management for any app
Stars
2,031Last commit
21 hours agoLicense
Apache-2.0
Authgear is a managed IAM platform handling authentication, SSO, and user management for B2C and B2B apps, with biometrics, MFA, and zero-trust support.
Open Source Alternative to:
Secure password manager with end-to-end encryption
Stars
2,920Last commit
1 year agoLicense
AGPL-3.0
Open-source password manager with end-to-end encryption for passwords, credit cards, notes, and documents. Cross-platform sync with secure sharing capabilities.
Open Source Alternative to:
Privacy-first proof-of-work CAPTCHA without user friction
Stars
2,488Last commit
11 months agoLicense
AGPL-3.0
Privacy-focused proof-of-work CAPTCHA system that silently protects websites without tracking users or requiring image solving. Drop-in replacement for reCAPTCHA.
Open Source Alternative to:
Secure collaboration platform with end-to-end encryption
Stars
2,546Last commit
8 months agoLicense
GPL-3.0
A comprehensive collaboration platform offering end-to-end encrypted messaging, file sharing, and video calls with enterprise-grade security and compliance features.
Open Source Alternative to:
Your secure French personal cloud for complete data control
Stars
1,269Last commit
16 hours agoLicense
AGPL-3.0
Open-source personal cloud that automatically gathers all your data from third-party services. French-hosted with privacy-first design, no ads, and seamless device sync.
Open Source Alternative to:
Secure secret management with public key encryption
Stars
767Last commit
5 months agoLicense
MPL-2.0
Secure secret management platform with public key encryption, automated rotation, versioning, and real-time collaboration tools for development teams.
Open Source Alternative to:
Secure, deploy, and manage application secrets effortlessly
Stars
915Last commit
16 hours agoLicense
MIT
Open source platform for engineering teams to manage secrets and environment variables from development to production, with powerful integrations.
Open Source Alternative to:
Feature management with GitOps for developers
Stars
807Last commit
13 hours agoLicense
MIT
Featurevisor is an open-source tool for managing feature flags, experiments, and remote configuration directly from your Git repository.
Open Source Alternative to:
Fast, minimal VPN built on modern cryptography
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711Last commit
4 months agoLicense
GPL-2.0
VPN protocol that runs inside the Linux kernel, using public-key cryptography to create encrypted tunnels across UDP with minimal configuration.
Open Source Alternative to:
Complete password control, zero cloud dependency
Stars
533Last commit
26 days agoLicense
Apache-2.0
Open-source password manager with peer-to-peer syncing, local storage, and end-to-end encryption. No cloud servers, complete privacy control across devices.
Open Source Alternative to:
Real-time fraud detection and AML compliance engine
Stars
597Last commit
2 days agoLicense
Elastic-2.0
An open-source platform that enables fintech companies to monitor transactions and user activity, detect suspicious behaviors, and automate fraud prevention in real-time.
Open Source Alternative to:
Decentralized CAPTCHA for enhanced web security
Stars
298Last commit
12 hours agoLicense
Apache-2.0
A blockchain-based CAPTCHA solution offering improved security, user experience, and resistance to bot attacks for web applications.
Open Source Alternative to:
GDPR-compliant bot protection without user friction
Stars
193Last commit
12 hours agoLicense
Unknown
Privacy-first CAPTCHA service that blocks bots while keeping forms accessible. No puzzles, no tracking, no cookies - just invisible cryptographic protection.
Open Source Alternative to:
Secure, scalable chat server for modern applications
Stars
158Last commit
12 days agoLicense
GPL-3.0
Open source chat server with end-to-end encryption, clustering support, and comprehensive messaging features for building real-time communication apps
Open Source Alternative to:
Secure, scalable server access management for DevOps
Stars
169Last commit
1 month agoLicense
BUSL-1.1
Centralized platform for managing SSH access, enhancing security, and streamlining server administration for DevOps teams.
Type-safe feature flags and remote config for developers
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166Last commit
1 year agoLicense
AGPL-3.0
Abby offers open-source, fully typed feature flagging and remote configuration for React and Next.js, with multi-environment testing and debugging tools.
Open Source Alternative to:
Invisible bot protection that respects user privacy
Stars
33Last commit
6 days agoLicense
MPL-2.0
Privacy-compliant CAPTCHA alternative using proof-of-work technology. Protects websites from bots and spam without user interaction or data tracking.
Open Source Alternative to:
Docmost – Open-source wiki software with real-time collaboration, diagrams, AI, SSO, RBAC permissions and more.
Docmost
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