Captcha (BYO keys)
Add reCAPTCHA, hCaptcha or Turnstile to any form
Paste your site key and secret into a form’s settings, add the provider’s widget to your page, and FormSubmit verifies every token server-side before accepting the submission. Works with reCAPTCHA v2 (checkbox), reCAPTCHA v3 (score threshold), hCaptcha and Cloudflare Turnstile.
Your keys, your account
You own the captcha relationship and analytics. Secrets are encrypted at rest with AES-256-GCM.
Score threshold
For reCAPTCHA v3, choose the minimum score (default 0.5).
Clear errors
Failed checks return captcha_failed for JavaScript clients or a friendly error page for HTML forms.
<script src="https://challenges.cloudflare.com/turnstile/v0/api.js" async defer></script>
<form action="https://formsubmit.app/f/YOUR_FORM_ID" method="POST">
<input type="email" name="email" required>
<div class="cf-turnstile" data-sitekey="YOUR_SITE_KEY"></div>
<button>Send</button>
</form>Frequently asked questions
Which captcha should I choose?
Cloudflare Turnstile is free and usually invisible to people. reCAPTCHA v3 is invisible and score-based. hCaptcha and reCAPTCHA v2 show a challenge.
Related
Captcha
Add Google reCAPTCHA v2/v3, hCaptcha or Cloudflare Turnstile to your forms with your own keys.
Spam protection
Honeypots, timing checks, content heuristics, rate limiting and optional captchas — on every plan.
How to stop contact form spam (without annoying real people)
A practical, layered approach to form spam — honeypots, timing checks, content filters, allowlists and captchas — and how to set each up.
Your form backend is 60 seconds away
Sign in with Google, create a form, paste the endpoint. Free forever for small sites — no credit card.