Form protection that
respects your users' privacy

A lightweight, secure CAPTCHA widget for any website. No fingerprinting, zero cookies, sub-second verification.

Why CaptchaTool

Privacy-first form protection without the baggage.

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Privacy-Friendly

No fingerprinting, no cookies, no profiling. We log only what's needed for abuse prevention — nothing more.

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Drop-In Integration

One script tag, three hidden inputs, done. Works with any framework, any form, any backend.

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Sub-Second Validation

Challenges resolve in under 200ms. No waiting, no frustration — just a single checkbox click.

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Cryptographic Security

Every proof token is cryptographically signed, tamper-proof, and single-use. No replay attacks, no forgery.

How It Works

Three API calls. That's all it takes.

1

Generate

Widget requests a challenge token from the API using your public site key.

2

Validate

User checks the box, widget sends the answer, and receives a signed proof token.

3

Verify

Your server sends the proof to our API and gets a definitive pass/fail response.

Try It Live

This demo runs on our verified domain. Enter your email and complete the CAPTCHA to see the full flow in action — the widget only loads on domains you've registered and verified.

No tracking. No cookies.

CAPTCHA

Quick Start

Add this snippet to any HTML form. The widget only loads on domains you've verified in your dashboard.

<script src="https://captchatool.com/widget/captcha-widget.min.js" defer></script>

<form method="POST" action="/your-handler">
  <input type="hidden" name="captcha_id" />
  <input type="hidden" name="captcha_proof" />
  <input type="hidden" name="botCheck" autocomplete="off" />

  <div data-captcha data-sitekey="pk_live_YOUR_SITE_KEY"></div>

  <button type="submit">Submit</button>
</form>