Form protection that
respects your users' privacy

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

See it work

Check the box. Watch what happens underneath.

Live The real widget, running on this page
Check the box
What actually happens
  1. Challenge issued
  2. Proof-of-work solved
  3. Answer validated
  4. Signed proof issued
0 cookies 0 trackers 0 personal data collected

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.

#!

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.

Simple, transparent pricing

Free to start · no credit card required. Upgrade only when you grow.

Free

$0 /month

To get started. No credit card required.

  • 1 project
  • 1 domain
  • 5,000 validations / month
Start free
Most popular

Solo

$9 /month

For growing sites.

  • 10 projects
  • 10 domains
  • 100,000 validations / month
Start free

Agency

$29 /month

For teams and multiple clients.

  • 100 projects
  • 100 domains
  • Unlimited site keys
  • 500,000 validations / month
Start free

Enterprise

Custom

For high volume and custom needs.

  • Unlimited projects & domains
  • Unlimited validations
  • Priority support
Contact sales

Quick Start

Two files. One tag on the page, one check on your server.

Drop it in — the widget only loads on domains you've verified.