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ALTCHA review

Freemium#13 of 32 in CAPTCHA Software

An open-source CAPTCHA with flexible cloud, self-hosted, and WordPress options.

7.7/10Editor score
Visit ALTCHA
ALTCHA7.7 Visit ALTCHA

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

ALTCHA provides CAPTCHA and bot protection for websites, applications, and WordPress. Its open-source core centers on an invisible proof-of-work widget, while Cloud and self-hosted Sentinel add adaptive verification and other protection features. It suits developers who want to choose between running the core themselves, using managed EU hosting, or deploying a WordPress-specific plan. Visual and audio challenges are available for flagged traffic, giving it more than a single CAPTCHA mode.

The deployment and integration options are a major part of ALTCHA’s fit. The product lists web and mobile support, a web component with configurable display modes and themes, and server libraries for multiple programming languages. Integrations include React, Vue, Svelte, Angular, Flutter, React Native, Django, and WordPress. Teams can choose Cloud for managed EU hosting, or Sentinel for self-hosting; Sentinel Enterprise adds unlimited instances and clusters, SSO, audit logs, and OpenTelemetry. This range makes ALTCHA relevant to both application developers and organizations with their own infrastructure, though self-hosting entails managing deployment and clustering.

Pricing separates the open-source core from managed and self-hosted paid tiers. The core is MIT licensed and self-hosted. Cloud is €47 per month; Cloud Plus is €137 and Cloud Max is €187, with 10x and 20x Cloud API capacity respectively. Sentinel Professional is €99 per month, while Sentinel Enterprise is €799 per month. WordPress Professional costs €18.90 per month and covers protection for 22+ plugins with unlimited verifications and invisible mode. Cloud and Sentinel offer a 30-day trial without a credit card. ALTCHA is a strong fit for teams seeking open-source control or deployment choice; teams wanting a basic hosted CAPTCHA without managing infrastructure or selecting among tiers may prefer a narrower option.

ALTCHA pros and cons

  • Where it wins
    • Invisible proof-of-work can verify browsers without a visible challenge.
    • Risk-based escalation can add visual or audio challenges for flagged traffic.
    • Integrates with web frameworks, mobile SDKs, server libraries, and WordPress.
  • Where it doesn't
    • Advanced protection features require a paid Cloud or Sentinel plan.
    • Self-hosted Sentinel requires teams to manage their own deployment.
    • Cloud API capacity varies by tier, with higher capacity on Cloud Plus and Max.

ALTCHA fact sheet, pricing and score →

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