# Get Started with ALTCHA

ALTCHA (*“Alternative CAPTCHA”*) provides a modern, privacy-focused alternative to reCAPTCHA and other legacy CAPTCHA systems. Instead of relying on intrusive tracking, it uses a [proof-of-work](/docs/integration/widget/#algorithms) mechanism, along with [advanced threat detection methods](/docs/sentinel/) when integrated with [ALTCHA Sentinel](/docs/sentinel/).

ALTCHA is fully self-hosted, ensuring strong data privacy and compliance with modern regulatory standards.

## Why ALTCHA?

* Frictionless experience for most users (no interaction required)
* Effectively blocks advanced bots and abuse
* Privacy-focused: no cookies, no tracking, and [GDPR-compliant](/legal/compliance/gdpr/)
* Accessible and [WCAG-compliant](/legal/compliance/wcag/)
* [Open-source core](/docs/integration/widget/) for transparency and control
* Lightweight and fast-loading for optimal performance
* Flexible, with [developer-friendly integration](/docs/integration/widget/)
* Enhanced protection when combined with [ALTCHA Sentinel](/docs/sentinel/)

## Open-Source

The open-source core of ALTCHA allows you to integrate privacy-first bot protection completetely free, without any external services.

1. [Widget](/docs/integration/widget/) - JavaScript component that handles proof-of-work verification and user interaction with customizable UI options and lightweight implementation.
3. [Libraries](/docs/integration/server/#libraries) - Server-side tools for payload validation and verification, supporting multiple programming languages.

## Commercial Products

1. [Sentinel Self-Hosted](/docs/sentinel/) - Self-hosted all-in-one spam protection platform that combines proof-of-work with machine learning and pattern recognition to block abuse while maintaining full privacy compliance. Recommended for production environments requiring robust protection.
2. [Cloud](/docs/cloud/) - Fully managed, EU-hosted bot protection powered by ALTCHA Sentinel. No infrastructure to run, with adaptive CAPTCHA and privacy-first design built in.
3. [WordPress Plugin](/docs/wordpress/) - Drop-in bot protection for WordPress forms and logins, powered by Sentinel or Cloud.

## Find Your Solution

One solution does not fit all, which is why ALTCHA offers a different recommended path depending on who you are and what you need. See the [Solutions overview](/docs/solutions/) for the full breakdown, or jump straight to your case:

* **[Individuals](/docs/solutions/individuals/)** — Personal sites, blogs, and side projects. Start with the free open-source widget or the WordPress plugin, and upgrade to [ALTCHA Cloud](/docs/cloud/) if you need adaptive protection without running a server yourself.
* **[Businesses](/docs/solutions/businesses/)** — E-commerce, SaaS, marketplaces, and agencies. Stop checkout fraud, fake sign-ups, and credential stuffing with [ALTCHA Cloud](/docs/cloud/), a fully managed, EU-hosted service — or self-host with [ALTCHA Sentinel](/docs/sentinel/) if you need full infrastructure control.
* **[Enterprises](/docs/solutions/enterprises/)** — Larger organizations with their own security and infrastructure requirements. [ALTCHA Sentinel](/docs/sentinel/) runs entirely on your infrastructure, with SSO, role-based access, clustering, and SLA-backed support.
* **[Governments](/docs/solutions/governments/)** — Public sector and government agencies. [ALTCHA Sentinel](/docs/sentinel/) supports statutory compliance, [WCAG-compliant](/legal/compliance/wcag/) accessibility, data sovereignty, and platform ownership through perpetual licensing.