Procaptcha: the GDPR-compliant CAPTCHA widget

Who Procaptcha is for

Teams migrating off reCAPTCHA or hCaptcha because:

• your DPO flagged the third-party tracking cookies and cross-site behavioural profile,
• EU or UK data-residency is on the roadmap,
• reCAPTCHA v2 or v3 is due to reprice under the new billing model,
• or the current widget is quietly letting scrapers, credential-stuffing tools and disposable-signup bots through.

Where you install it

Anywhere you'd put a CAPTCHA today:

• Login forms — stop credential-stuffing without adding another hop for real users.
• Signup and registration — cut disposable-email and throwaway-account traffic before it hits your database.
• Checkout and payment — block scalper and reseller automation on high-value purchases.
• Contact and support forms — keep spam out without a cookie banner update.
• Comment and review submissions — stop review-farm and forum-spam bots.

How you install it

Two files change on your site: the script tag on the page, and the verify call in your backend.

On the form — drop the script and the widget container:

<script src="https://js.prosopo.io/js/procaptcha.bundle.js" async defer></script>

<form method="POST" action="/login">
  <input name="email" type="email">
  <input name="password" type="password">
  <div data-sitekey="YOUR_SITE_KEY" class="procaptcha"></div>
  <button type="submit">Sign in</button>
</form>

In the backend — verify the token before you trust the submission:

const res = await fetch("https://api.prosopo.io/siteverify", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ secret: process.env.PROSOPO_SECRET, token }),
});
const { verified, reason } = await res.json();
if (!verified) return reject(reason);

The response has the same shape as reCAPTCHA and hCaptcha, so most existing verification code needs a URL change and nothing else. Every verdict comes back with a reason your team can read — a specific detector name rather than a numerical score.

How it compares to reCAPTCHA, hCaptcha and Turnstile

Procaptcha vs Prosopo Protect

Procaptcha is the widget you drop on individual forms. Prosopo Protect is the edge-deployed sibling that wraps every request to a site or API. Same detection engine, different scope.

Integration reference

• Get started — site key setup, widget install, first verification.
• Server-side verification — verify tokens in your backend.
• Framework integrations — React, Vue, Angular, Svelte.
• Procaptcha vs reCAPTCHA — side-by-side data controller, pricing and catch-rate comparison.
• Procaptcha vs hCaptcha — how the two compare on GDPR and detection.

Having a problem on a live site? Use Prosopo Support and include the URL where the issue is happening.