# 6 Best Open Source Alternatives for Cloudflare Turnstile Canonical: https://caniforkit.com/cloudflare-turnstile Last updated: 2026-11-07 Looking for the best open source alternative for Cloudflare Turnstile? Compare 6 verified free and open source alternatives to Cloudflare Turnstile (Cap, ALTCHA, mCaptcha) with license details, self-hosting requirements, and practical trade-offs. ## Cloudflare Turnstile Overview & Subscription Cost - **Product**: Cloudflare Turnstile - **Category**: [automation](https://caniforkit.com/category/automation) - **Paid Subscription Price**: $15/month per seat - **1-Seat Annualized Cost**: $180/year - **5-Person Team Annualized Cost**: $900/year - **10-Person Team Annualized Cost**: $1,800/year - **Can I Vibe-Code / Rebuild It Myself?**: NO (use a free alternative, save the tokens) - **Rebuild Verdict**: Instead of paying recurring SaaS fees for Cloudflare Turnstile or rebuilding it from scratch, deploy one of the 6 battle-tested open-source alternatives like Cap. ## Verified Free & Open Source Alternatives | Alternative | Type | License | Runs On | GitHub Stars | Head-to-Head | | --- | --- | --- | --- | --- | --- | | [Cap](https://caniforkit.com/fork/capjs) | Open Source | Open Source | Self-host | ★ 8.3k | [Compare vs Cloudflare Turnstile](https://caniforkit.com/vs/cloudflare-turnstile-vs-capjs) | | [ALTCHA](https://caniforkit.com/fork/altcha) | Open Source | Open Source | Self-host | ★ 2.9k | [Compare vs Cloudflare Turnstile](https://caniforkit.com/vs/cloudflare-turnstile-vs-altcha) | | [mCaptcha](https://caniforkit.com/fork/mcaptcha) | Open Source | Open Source | Self-host | ★ 2.5k | [Compare vs Cloudflare Turnstile](https://caniforkit.com/vs/cloudflare-turnstile-vs-mcaptcha) | | [Procaptcha](https://caniforkit.com/fork/procaptcha) | Open Source | Open Source | Local | ★ 303 | [Compare vs Cloudflare Turnstile](https://caniforkit.com/vs/cloudflare-turnstile-vs-procaptcha) | | [Private Captcha](https://caniforkit.com/fork/private-captcha) | Open Source | Open Source | Self-host | ★ 199 | [Compare vs Cloudflare Turnstile](https://caniforkit.com/vs/cloudflare-turnstile-vs-private-captcha) | | [Friendly Captcha](https://caniforkit.com/fork/friendly-captcha) | Open Source | Open Source | Local | ★ 37 | [Compare vs Cloudflare Turnstile](https://caniforkit.com/vs/cloudflare-turnstile-vs-friendly-captcha) | ## In-Depth Alternative Profiles ### Cap - **Fork Page**: [Cap Profile](https://caniforkit.com/fork/capjs) - **Head-to-Head Comparison**: [Cloudflare Turnstile vs Cap](https://caniforkit.com/vs/cloudflare-turnstile-vs-capjs) - **Official Website**: https://capjs.js.org/ - **Source Code Repository**: https://github.com/tiagozip/cap - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 8.3k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Lightweight open-source CAPTCHA solution using SHA-256 proof-of-work. 250x smaller than hCaptcha, fully customizable, and privacy-focused with zero telemetry. - **The Catch vs Cloudflare Turnstile**: Requires self-hosting setup, updates, and server maintenance compared to managed Cloudflare Turnstile. - **Installation**: Clone https://github.com/tiagozip/cap or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### ALTCHA - **Fork Page**: [ALTCHA Profile](https://caniforkit.com/fork/altcha) - **Head-to-Head Comparison**: [Cloudflare Turnstile vs ALTCHA](https://caniforkit.com/vs/cloudflare-turnstile-vs-altcha) - **Official Website**: https://altcha.org - **Source Code Repository**: https://github.com/altcha-org/altcha - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 2.9k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: ALTCHA offers cutting-edge spam and abuse protection for websites and apps, with privacy-friendly CAPTCHA alternatives designed for GDPR compliance. - **The Catch vs Cloudflare Turnstile**: Requires self-hosting setup, updates, and server maintenance compared to managed Cloudflare Turnstile. - **Installation**: Clone https://github.com/altcha-org/altcha or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### mCaptcha - **Fork Page**: [mCaptcha Profile](https://caniforkit.com/fork/mcaptcha) - **Head-to-Head Comparison**: [Cloudflare Turnstile vs mCaptcha](https://caniforkit.com/vs/cloudflare-turnstile-vs-mcaptcha) - **Official Website**: https://mcaptcha.org - **Source Code Repository**: https://github.com/mcaptcha/mcaptcha - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 2.5k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Privacy-focused proof-of-work CAPTCHA system that silently protects websites without tracking users or requiring image solving. Drop-in replacement for reCAPTCHA. - **The Catch vs Cloudflare Turnstile**: Requires self-hosting setup, updates, and server maintenance compared to managed Cloudflare Turnstile. - **Installation**: Clone https://github.com/mcaptcha/mcaptcha or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### Procaptcha - **Fork Page**: [Procaptcha Profile](https://caniforkit.com/fork/procaptcha) - **Head-to-Head Comparison**: [Cloudflare Turnstile vs Procaptcha](https://caniforkit.com/vs/cloudflare-turnstile-vs-procaptcha) - **Official Website**: https://prosopo.io/ - **Source Code Repository**: https://github.com/prosopo/captcha - **License**: Open Source - **Runs On**: Local - **GitHub Stars**: 303 - **Maintenance Activity**: nov 2026 - **Supported Platforms**: desktop, cross-platform, one-click install - **Summary**: A blockchain-based CAPTCHA solution offering improved security, user experience, and resistance to bot attacks for web applications. - **The Catch vs Cloudflare Turnstile**: Community-driven open source project without dedicated enterprise SLAs. - **Installation**: Clone https://github.com/prosopo/captcha or deploy with Docker Compose - **Setup**: Download the native package or installer for your operating system. - **Data Storage**: All application data lives locally on your own machine. ### Private Captcha - **Fork Page**: [Private Captcha Profile](https://caniforkit.com/fork/private-captcha) - **Head-to-Head Comparison**: [Cloudflare Turnstile vs Private Captcha](https://caniforkit.com/vs/cloudflare-turnstile-vs-private-captcha) - **Official Website**: https://privatecaptcha.com/ - **Source Code Repository**: https://github.com/privatecaptcha/privatecaptcha - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 199 - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Privacy-first CAPTCHA service that blocks bots while keeping forms accessible. No puzzles, no tracking, no cookies - just invisible cryptographic protection. - **The Catch vs Cloudflare Turnstile**: Requires self-hosting setup, updates, and server maintenance compared to managed Cloudflare Turnstile. - **Installation**: Clone https://github.com/privatecaptcha/privatecaptcha or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### Friendly Captcha - **Fork Page**: [Friendly Captcha Profile](https://caniforkit.com/fork/friendly-captcha) - **Head-to-Head Comparison**: [Cloudflare Turnstile vs Friendly Captcha](https://caniforkit.com/vs/cloudflare-turnstile-vs-friendly-captcha) - **Official Website**: https://friendlycaptcha.com/ - **Source Code Repository**: https://github.com/FriendlyCaptcha/friendly-captcha-sdk - **License**: Open Source - **Runs On**: Local - **GitHub Stars**: 37 - **Maintenance Activity**: nov 2026 - **Supported Platforms**: desktop, cross-platform, one-click install - **Summary**: Privacy-compliant CAPTCHA alternative using proof-of-work technology. Protects websites from bots and spam without user interaction or data tracking. - **The Catch vs Cloudflare Turnstile**: Community-driven open source project without dedicated enterprise SLAs. - **Installation**: Clone https://github.com/FriendlyCaptcha/friendly-captcha-sdk or deploy with Docker Compose - **Setup**: Download the native package or installer for your operating system. - **Data Storage**: All application data lives locally on your own machine. ## Frequently Asked Questions ### What is the best free alternative to Cloudflare Turnstile? The top free alternative to Cloudflare Turnstile is Cap (open source, Open Source). Lightweight open-source CAPTCHA solution using SHA-256 proof-of-work. 250x smaller than hCaptcha, fully customizable, and privacy-focused with zero telemetry. Other popular Cloudflare Turnstile replacements include ALTCHA, mCaptcha, Procaptcha. ### How much does switching from Cloudflare Turnstile to a free alternative save? Cloudflare Turnstile starts at $15/month per seat ($180/year). Switching a 5-person team to a free alternative like Cap saves $900 per year in software subscription fees. ### What is the catch when switching away from Cloudflare Turnstile? While Cap replaces core Cloudflare Turnstile features without subscription fees, the real-world trade-off is: Requires self-hosting setup, updates, and server maintenance compared to managed Cloudflare Turnstile. ## Related - [automation Software Category Hub](https://caniforkit.com/category/automation) - [All Paid SaaS Alternatives Index](https://caniforkit.com/alternatives) - [Self-Hosted Software Directory](https://caniforkit.com/self-hosted) - [Homepage](https://caniforkit.com)