# ALTCHA > ALTCHA is a privacy-first CAPTCHA alternative that uses a proof-of-work mechanism to protect your website from spam and bots. ## Main Pages - [ALTCHA — Privacy-First CAPTCHA Alternative](/index.md): ALTCHA protects your site from bots and spam with a privacy-first CAPTCHA — no tracking, no cookies, fully GDPR compliant and WCAG 2.2 AA accessible. - [Pricing - ALTCHA](/pricing.md): Compare ALTCHA Cloud, self-hosted, and Sentinel pricing. Get 2 months free with annual billing. - [About - ALTCHA](/about.md): ALTCHA builds privacy-first, self-hosted bot protection — accessible and transparent, and built in the EU for organizations with demanding compliance requirements. ## Getting Started - [Introduction](/docs/index.md): ALTCHA is a privacy-first CAPTCHA alternative that uses a proof-of-work mechanism to protect your website from spam and bots. - [How ALTCHA Works](/docs/how-it-works.md): A high-level overview of how ALTCHA verifies visitors — without puzzles, tracking, or third-party API calls. - [Why Organizations Trust ALTCHA](/docs/trust.md): The evidence behind ALTCHA's trust — adoption, compliance, security practices, and data sovereignty. - [Open Source vs. Paid](/docs/open-source-vs-paid.md): A simple breakdown of what's free forever in ALTCHA, and what Cloud and Sentinel add on top. - [Legal & Compliance](/legal.md) - [FAQ](/faq.md) ## Solutions - [Solutions](/docs/solutions.md): Which ALTCHA solution fits your website, business, or organization — open-source, WordPress, Cloud, or Sentinel. - [Solutions For Individuals](/docs/solutions/individuals.md) - [Solutions For Businesses](/docs/solutions/businesses.md) - [Solutions For Enterprises](/docs/solutions/enterprises.md) - [Solutions For Governments](/docs/solutions/governments.md) ## Integration - [Quick Start](/docs/integration/quick-start.md): Get ALTCHA up and running in 5 minutes. - [Widget Integration](/docs/integration/widget.md) - [Server Integration](/docs/integration/server.md) - [Widget Customization](/docs/integration/widget-customization.md) - [Obfuscation](/docs/integration/obfuscation.md) - [Troubleshooting](/docs/integration/troubleshooting.md) - [Security Recommendations](/docs/integration/security-recommendations.md): TBD - [Diagrams](/docs/integration/diagrams.md) - [Proof Of Work Captcha](/docs/integration/proof-of-work-captcha.md): ALTCHA is a modern proof-of-work CAPTCHA that stops bots without tracking users or slowing down your site. Fast, private, and user-friendly. ## Migrations - [Migrate from reCAPTCHA](/docs/migration/recaptcha.md): Replace Google reCAPTCHA with ALTCHA's self-hosted, proof-of-work widget. - [Migrate from hCaptcha](/docs/migration/hcaptcha.md): Replace hCaptcha with ALTCHA's self-hosted, proof-of-work widget. - [Migrate from Cloudflare Turnstile](/docs/migration/turnstile.md): Replace Cloudflare Turnstile with ALTCHA's self-hosted, proof-of-work widget. ## Cloud - [Introduction to ALTCHA Cloud](/docs/cloud.md): TBD - [Quick Start with ALTCHA Cloud](/docs/cloud/quick-start.md): TBD - [Settings for ALTCHA Cloud](/docs/cloud/settings.md): Configure protection levels, proof-of-work algorithms, code challenges, and other options for your ALTCHA Cloud sites. ## Sentinel - [Introduction to Sentinel](/docs/sentinel.md): What ALTCHA Sentinel is, how it works, and when to use it instead of (or alongside) open-source ALTCHA. - [Get Started with Sentinel](/docs/sentinel/get-started.md): Deploy ALTCHA Sentinel and protect your first form in about 15 minutes. - [Plans & Limits](/docs/sentinel/plans.md): How ALTCHA Sentinel licensing tiers compare — instance, account, and user limits, database support, and which features each plan unlocks. - [Databases](/docs/sentinel/databases.md): Supported database backends for ALTCHA Sentinel — main database, KV store, and logs/analytics. - [Integration Checklist](/docs/sentinel/integration-checklist.md): Launch-readiness checklist for a production ALTCHA Sentinel deployment. - [Releases](/docs/sentinel/releases.md) ## WordPress - [Introduction to ALTCHA for WordPress](/docs/wordpress.md): What the ALTCHA WordPress plugin does, why it's different from CAPTCHA services, and where to start. - [Get Started with WordPress](/docs/wordpress/get-started.md): Install the ALTCHA WordPress plugin and confirm it's protecting your site in a few minutes. - [Features](/docs/wordpress/features.md): Say goodbye to spam, abuse, and frustrating CAPTCHAs — everything the ALTCHA WordPress plugin does to keep bots out and real users in. - [Configuration](/docs/wordpress/configuration.md): Every setting in the ALTCHA WordPress plugin — modes, verification bypass, actions, paths, analytics, firewall, and rate limiting. - [Advanced](/docs/wordpress/advanced.md): Shortcodes, obfuscation, custom handlers, hooks, plugin integrations, cookies, CDN caching, and how-to recipes. - [Troubleshooting](/docs/wordpress/troubleshooting.md): Debug mode, verifying that ALTCHA is active, API caching, and fixes for common WordPress plugin issues. - [Releases](/docs/wordpress/releases.md) ## Legal & Compliance - [General Information](/legal/general.md): Company information, copyright, and trademarks. - [Privacy Policy](/legal/privacy.md): How ALTCHA collects, uses, and protects your data. - [Terms of Service](/legal/terms.md): The terms that govern your use of ALTCHA Cloud services. - [Regulatory Compliance](/legal/compliance.md): Documentation on GDPR and other regulatory compliance requirements. - [Data Processing Agreement (DPA)](/legal/dpa.md): DPA documentation for ALTCHA Sentinel (self-hosted) and ALTCHA Cloud. - [Security Compliance Framework](/legal/security-framework.md): Security compliance framework for ALTCHA Sentinel self-hosted deployments. - [Security Vulnerability Disclosure Policy](/legal/security.md): Our vulnerability reporting and disclosure policy. - [Security Advisory](/legal/security-advisory.md): Disclosed vulnerabilities related to ALTCHA products. - [ALTCHA Sentinel — End-User License Agreement (EULA)](/legal/sentinel/eula.md): The license terms governing your use of ALTCHA Sentinel. - [ALTCHA Sentinel — Support Policy](/legal/sentinel/support.md): The support terms and services available for ALTCHA Sentinel. - [ALTCHA for WordPress — End-User License Agreement (EULA)](/legal/wordpress/eula.md): The license terms governing your use of ALTCHA for WordPress. - [ALTCHA for WordPress — Support Policy](/legal/wordpress/support.md): The support terms and services available for ALTCHA for WordPress. - [CCPA Compliance](/legal/compliance/ccpa.md) - [PIPEDA + CPPA Compliance](/legal/compliance/cppa.md) - [DPDPA Compliance](/legal/compliance/dpdpa.md) - [European Accessibility Act 2025 (EAA)](/legal/compliance/eaa.md) - [GDPR Compliance](/legal/compliance/gdpr.md) - [HIPAA Compliance](/legal/compliance/hipaa.md) - [LGPD Compliance](/legal/compliance/lgpd.md) - [PIPL Compliance](/legal/compliance/pipl.md) - [WCAG 2.2 Compliance](/legal/compliance/wcag.md) ## GitHub Repositories Links point to each repo's README (usage examples + API), the reliable single file to fetch directly without browsing the repo. - [altcha-org/altcha](https://raw.githubusercontent.com/altcha-org/altcha/main/README.md): Main repository — the ALTCHA widget (JS/TS web component), MIT licensed. Server-side verification libraries: - [altcha-lib](https://raw.githubusercontent.com/altcha-org/altcha-lib/main/README.md) (JS/TS) - [altcha-lib-py](https://raw.githubusercontent.com/altcha-org/altcha-lib-py/main/README.md) (Python) - [altcha-lib-go](https://raw.githubusercontent.com/altcha-org/altcha-lib-go/main/README.md) (Go) - [altcha-lib-php](https://raw.githubusercontent.com/altcha-org/altcha-lib-php/main/README.md) (PHP) - [altcha-lib-java](https://raw.githubusercontent.com/altcha-org/altcha-lib-java/main/README.md) (Java) - [altcha-lib-rb](https://raw.githubusercontent.com/altcha-org/altcha-lib-rb/main/README.md) (Ruby) - [altcha-lib-rs](https://raw.githubusercontent.com/altcha-org/altcha-lib-rs/main/README.md) (Rust) - [altcha-lib-cpp](https://raw.githubusercontent.com/altcha-org/altcha-lib-cpp/main/README.md) (C++) - [altcha-lib-dart](https://raw.githubusercontent.com/altcha-org/altcha-lib-dart/main/README.md) (Dart) - [altcha-lib-ex](https://raw.githubusercontent.com/altcha-org/altcha-lib-ex/main/README.md) (Elixir) Mobile widgets: - [altcha-flutter](https://raw.githubusercontent.com/altcha-org/altcha-flutter/main/README.md) - [altcha-react-native](https://raw.githubusercontent.com/altcha-org/altcha-react-native/main/README.md) Framework starters (widget already wired up, ready to run): - [altcha-starter-react-ts](https://raw.githubusercontent.com/altcha-org/altcha-starter-react-ts/main/README.md) - [altcha-starter-vue-ts](https://raw.githubusercontent.com/altcha-org/altcha-starter-vue-ts/main/README.md) - [altcha-starter-svelte-ts](https://raw.githubusercontent.com/altcha-org/altcha-starter-svelte-ts/main/README.md) - [altcha-starter-solid-ts](https://raw.githubusercontent.com/altcha-org/altcha-starter-solid-ts/main/README.md) - [altcha-starter-lit-ts](https://raw.githubusercontent.com/altcha-org/altcha-starter-lit-ts/main/README.md) - [altcha-starter-angular](https://raw.githubusercontent.com/altcha-org/altcha-starter-angular/main/README.md) ## Skills - [ALTCHA Integration](/.well-known/agent-skills/altcha-integration/SKILL.md): Add ALTCHA, a free and open-source, privacy-friendly proof-of-work CAPTCHA alternative, to a website or app. Covers embedding the web component in a form, generating single-use challenges on the server, and verifying submitted solutions with an official ALTCHA library (or ALTCHA Sentinel/Cloud). Use when asked to add ALTCHA, protect a form from bots/spam, replace reCAPTCHA/hCaptcha/Cloudflare Turnstile with ALTCHA, or debug an ALTCHA widget/challenge/verification issue.