Captcha Setup
Protect your forms from spam and bots with human verification.
All captcha providers
| Provider | Type | Plan | Get keys |
|---|---|---|---|
| FormShield | Invisible (automatic) | All plans | No keys needed |
| Math Challenge | Visible (e.g. "What is 3+7?") | All plans | No keys needed |
| hCaptcha | Checkbox + puzzles | All plans | dashboard.hcaptcha.com |
| reCAPTCHA v2 | Checkbox + image puzzles | Pro | Google Cloud Console |
| reCAPTCHA v3 | Invisible (score-based) | Pro | Google Cloud Console |
| Cloudflare Turnstile | Invisible (no puzzles) | Pro | dash.cloudflare.com/turnstile |
| GeeTest v4 | Behavioral (slide/click) | Pro | geetest.com |
Pricing and limits
All captcha providers supported by FormBlade have a free tier. Here is what each offers (as of April 2026 — check provider websites for current pricing):
| Provider | Free tier | Monthly limit | Credit card | Paid plans |
|---|---|---|---|---|
| FormShield | Built-in | Unlimited | Not needed | N/A — included with FormBlade |
| Math Challenge | Built-in | Unlimited | Not needed | N/A — included with FormBlade |
| hCaptcha | Free forever | 1,000,000 / month | Not needed | Pro ($99/mo, 5M), Business ($299/mo, 100M), Enterprise (custom) |
| reCAPTCHA v2 | Free | 10,000 assessments / month | Not needed for free tier | reCAPTCHA Enterprise: $1 per 1,000 assessments above free tier (first 10K free) |
| reCAPTCHA v3 | Free | 10,000 assessments / month | Not needed for free tier | Same as v2 — reCAPTCHA Enterprise pricing above 10K/month |
| Cloudflare Turnstile | Free forever | Unlimited | Not needed | No paid tiers — completely free with no caps |
| GeeTest v4 | Free trial | 300,000 / month (free) | Not needed for trial | Standard ($250/mo), Professional ($500/mo), Enterprise (custom) |
Best value: Cloudflare Turnstile is completely free with no limits and provides the best user experience (invisible, no puzzles). hCaptcha is the best free option if you need a visible challenge. reCAPTCHA's free tier (10K/month) is the most restrictive — most forms will stay within it, but high-traffic sites should consider Turnstile or hCaptcha instead.
Which one should I choose?
- Start with defaults — every FormBlade form has FormShield enabled automatically. In real-world testing, FormShield blocked over 98% of spam and bots with zero setup and zero user friction.
- Free and simple — add the Math Challenge. No external account needed, works everywhere including China.
- Free with strong protection — add hCaptcha. Privacy-friendly (no Google tracking), free up to 1M verifications/month. Available on all plans.
- Best UX (Pro) — Cloudflare Turnstile. Completely invisible, no puzzles, free unlimited. Users never see a challenge.
- Invisible scoring (Pro) — reCAPTCHA v3. Runs in the background, assigns a 0.0-1.0 score. Set a threshold (0.5 recommended).
- Asia / China (Pro) — GeeTest v4. Behavioral challenges that work without Google services.
How captcha works in FormBlade
- Pick a provider in the Form Designer → Captcha section.
- Add your keys — paste the Site Key and Secret Key from your captcha provider's dashboard. Math Challenge and FormShield need no keys.
- Save — on hosted forms (
/f/example), the widget appears automatically. On self-hosted forms, add the provider's script tag to your HTML (see the Integration tab for code). - Verification — when a form is submitted, FormBlade verifies the captcha token server-side. Failed verifications are accepted but flagged as spam (soft-fail). You never lose a submission.
Soft-fail: never lose a submission
Unlike most form services, FormBlade does not reject submissions that fail captcha. Instead, they are accepted and marked as spam in your dashboard. This means:
- Misconfigured keys or network errors do not block real users
- You can review flagged submissions and unflag false positives
- The Spam tab shows exactly which check triggered (FormShield or captcha)
- No notification emails are sent for spam-flagged submissions
Hosted forms vs self-hosted
- Hosted forms (
/f/example) — the captcha widget is injected automatically. No HTML changes needed. - Self-hosted forms — add the provider's script tag and widget to your HTML. The Integration tab in your form shows the exact code to copy.
Tip: Captcha stacks with FormShield. Both run independently on every submission, giving you layered protection.
Plan availability
| Feature | Personal (free) | Pro |
|---|---|---|
| FormShield verification | Yes (automatic) | Yes |
| Math Challenge | Yes | Yes |
| hCaptcha | Yes | Yes |
| reCAPTCHA v2 / v3 | No | Yes |
| Cloudflare Turnstile | No | Yes |
| GeeTest v4 | No | Yes |