ALTCHA
ALTCHA: An open-source CAPTCHA with flexible cloud, self-hosted, and WordPress options. Ranked #13 of 32 in CAPTCHA Software by our editors (7.7/10); pricing: Free plan · 30-day trial; best for developers who want open-source or self-hosted CAPTCHA.
At a glance
- Editor score7.7 / 10
- PricingFree plan · 30-day trial
- Best forDevelopers who want open-source or self-hosted CAPTCHA
- Free planYes
- Paid from€18.90/mo
- CAPTCHA modesProof-of-work
- Facts checked22 Oct 2026
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.
Our verdict on ALTCHA
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.
Your product? Our editors can test ALTCHA in depth and publish a review, labelled as paid · from $149/mo →
ALTCHA pricing
All 10 ALTCHA plans and prices →
ALTCHA fact sheet
| Free plan | Yes |
|---|---|
| Paid from | €18.90/mo |
| CAPTCHA modes | Proof-of-work |
| Audio challenge | Yes |
| Accessibility options | Yes |
| Monthly verifications | Not verified |
| SDK platforms | Both |
| Privacy controls | Yes |
| Free trial | 30 days · no card needed |
| Deployment | Cloud, Self-hosted, Mobile |
| Platforms | Web, iOS, Android |
| Compliance & security | GDPR, HIPAA, 2FA |
| Support | Email, Live chat, Docs |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 20 integrations: React, Vue, Svelte, Solid, Lit, Angular … |
| Pricing | Free plan · 30-day trial (source) |
| Website | altcha.org |
| Facts checked | 22 Oct 2026 |
ALTCHA integrations
ALTCHA lists 20 integrations on its own site.
- React
- Vue
- Svelte
- Solid
- Lit
- Angular
- Flutter
- React Native
- WordPress
- Django
- C++
- Dart
- Dotnet
- Elixir
- Go
- Java
- JavaScript/TypeScript
- PHP
- Python
- Ruby
Alternatives to ALTCHA
- Cloudflare TurnstileA free CAPTCHA alternative with adaptive checks, invisible modes and server-side validation.9.4
- Google reCAPTCHAAdaptive bot protection with web and Android options and a free monthly allowance.9.2
- Alibaba Cloud CAPTCHAA managed CAPTCHA service with regional per-call pricing and policy controls.9.0
Used ALTCHA? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used ALTCHA for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
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Featured on iTechGuides
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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