Open Source Application Security Tools
A curated collection of the best open source tools for securing software applications during development and runtime.
Feature flags for rapid, risk-free software deployment
Stars
13,831Last commit
12 hours agoLicense
AGPL-3.0
A powerful feature management platform enabling gradual rollouts, A/B testing, and seamless integration for continuous delivery.
Open Source Alternative to:
Privacy-first CAPTCHA alternative with proof-of-work
Stars
7,856Last commit
2 days agoLicense
Apache-2.0
Lightweight open-source CAPTCHA solution using SHA-256 proof-of-work. 250x smaller than hCaptcha, fully customizable, and privacy-focused with zero telemetry.
Open Source Alternative to:
Open-source A/B testing and feature flagging platform
Stars
8,430Last commit
10 hours agoLicense
MIT
Powerful, developer-friendly experimentation tool for data-driven product decisions. Seamless integration, real-time insights, and flexible deployment.
Open Source Alternative to:
Feature flags and remote config for rapid deployment
Stars
6,570Last commit
10 hours agoLicense
BSD-3-Clause
Powerful feature management platform for seamless software releases, A/B testing, and personalized user experiences.
Open Source Alternative to:
Git-native feature management for developers
Stars
4,911Last commit
13 hours agoLicense
GPL-3.0
A feature flag platform that integrates with Git workflows, enabling developers to manage features directly in their codebase.
Open Source Alternative to:
Next-Gen CAPTCHA and Spam Protection, GDPR compliant
Stars
2,779Last commit
6 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:
Open-source feature flag management for seamless deployments
Stars
1,907Last commit
2 days 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:
Privacy-first proof-of-work CAPTCHA without user friction
Stars
2,493Last commit
1 year 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:
Feature management with GitOps for developers
Stars
810Last commit
17 days 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:
Decentralized CAPTCHA for enhanced web security
Stars
300Last commit
10 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
194Last commit
11 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:
Type-safe feature flags and remote config for developers
Stars
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
35Last commit
23 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:
CodeRabbit – The leading AI Code Review platform. Ship better quality code in 50% less time, with 90% fewer bugs.
Stellar Hosted
Sent