No Google. No Cloudflare lock-in. Your data stays yours.
Sentinel is a privacy-first captcha and human-verification service — a genuine alternative to reCAPTCHA, hCaptcha and Cloudflare Turnstile. Keep your existing forms, keep your visitors' data, and stop bots without handing anything to Big Tech.
The legacy captchas verify humans by watching them. Sentinel verifies humans on infrastructure you control — so the privacy story is yours to keep.
No visitor data handed to Google or Cloudflare, no cross-site tracking, no data sales. Sentinel only uses coarse, non-PII signals to tell humans from bots.
Run verification on infrastructure you control. Your reputation and challenge data stays yours, with no Big-Tech dependency wired into your sign-up and checkout flows.
Genuinely free for up to a million verifications every year, no card required. Paid tiers provide larger annual allowances for higher-volume sites.
Sentinel is more than a checkbox. It plugs into a self-owned IP-reputation intel API — geo, ASN, datacenter, VPN, Tor and abuse signals — so you can score risk, not just block bots.
An honest, feature-by-feature look. All four stop bots well — the real question is who owns the data and who you depend on.
| Feature | RedeyedPrivacy-first | reCAPTCHAGoogle | hCaptchaIntuition Machines | TurnstileCloudflare |
|---|---|---|---|---|
| Free tier | 1,000,000 / yr | ✓ | ✓ | ✓ |
| Self-hostable | ✓ | ✗ | ✗ | ✗ |
| No Google data collection | ✓ | ✗ | ✓ | ✓ |
| No Cloudflare dependency | ✓ | ✓ | ✓ | ✗ |
| Your data stays yours | ✓ | ✗ | ~ | ~ |
| Privacy-first / GDPR-friendly | ✓ | ~ | ✓ | ✓ |
| Invisible / low-friction option | ✓ | ~ | ~ | ✓ |
| Multiple widget types + theming | ✓ | ~ | ~ | ~ |
| IP-reputation intel API | ✓ | ✗ | ✗ | ✗ |
| Open / no vendor lock-in | ✓ | ✗ | ~ | ✗ |
| Works alongside your forms | ✓ | ✓ | ✓ | ✓ |
| Drop-in migration path | reCAPTCHA / hCaptcha / Turnstile-compatible | ~ | ~ | ~ |
~ = partial or varies by plan / configuration. Competitor details are accurate to the best of our knowledge at the time of writing and can change — always check each provider's current terms. Sentinel is free up to 1,000,000 verifications per year.
You do not have to rebuild your forms to move to Sentinel. Keep your existing markup and your server-side verify call — Sentinel ships drop-in compatibility for reCAPTCHA, hCaptcha and Turnstile, so in most cases you swap keys, point the verify request at Sentinel, and you are done.
Prefer a clean setup? Add the Sentinel widget tag and a single verify call and you get the same passed / challenged / blocked outcome, plus an optional risk score — all on infrastructure you own.
The honest answers on cost, privacy and switching from reCAPTCHA, hCaptcha or Turnstile.
Yes. Sentinel is free to use for up to 1,000,000 verifications every year, with no credit card required. That covers many small sites comfortably. If you later want monthly capacity or the developer IP-reputation intel API, paid plans and add-ons are available.
It is designed to be a drop-in reCAPTCHA alternative. You keep your existing form markup and server-side verify call, and Sentinel ships compatibility for reCAPTCHA, hCaptcha and Turnstile so most sites can switch in a few minutes. The difference is that Sentinel is privacy-first and self-hostable — you are not handing visitor data to a third party.
Yes. Sentinel can run on infrastructure you control, so verification stays inside your own estate. Your data stays yours, and there is no Big-Tech dependency baked into your sign-up and checkout flows.
No. Sentinel does not depend on Google or Cloudflare, and it does not ship your visitors' data off to them. Only coarse, non-PII signals are used to tell humans from bots, and those signals stay within your own deployment.
Because Sentinel is privacy-first and self-hostable, it avoids the cross-site tracking and third-party data sharing that make some legacy captchas hard to reconcile with GDPR. You keep control of the data, which makes a compliant setup much simpler.
Privacy-first, self-hostable, and free to 1,000,000 verifications a year. Stop bots without handing your visitors to Google or Cloudflare — the captcha you can actually call your own.
