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ALTCHA is a privacy-first, proof-of-work CAPTCHA alternative designed to protect your applications from bots, spam, and abuse without relying on tracking, fingerprinting, or invasive challenges. Unlike traditional CAPTCHA providers, ALTCHA is completely free and open-source, with no usage limits or paid tiers. Even better, when using Atomd, you do not need to generate or manage any keys — everything is securely self-hosted and handled for you. While ALTCHA is an excellent choice for full control, privacy, and cost efficiency, you may still consider Cloudflare Turnstile if you prefer a fully managed, plug-and-play solution with global infrastructure.

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In Atomd

To enable ALTCHA, simply navigate to your Atomd dashboard and toggle ALTCHA on.