NOVA Captcha
Human verification without the surveillance.
NOVA Captcha proves a visitor is a human the honest way: it asks their device to do a small, verifiable amount of work. No puzzles to train, no fingerprints, no third-party trackers, no image grids. Your device solves a SHA-256 proof-of-work locally and sends only the solution — never anything about you.
- Proof-of-work, not profilingDifficulty scales with load; solving costs CPU seconds, not personal data.
- No fingerprintingNo canvas tricks, no device IDs, no cross-site cookies.
- Nothing leaves your deviceYour browser or app mines locally; only the nonce is submitted.
- No third partiesIt is our own service, so there is no reCAPTCHA or hCaptcha dependency.
The challenge is split into several short stages so progress is smooth and a slow device is never punished with a single long search. Tokens are short-lived, single-use, and verified server-side — the client is never trusted.
Try it live
This is the real widget, running against the live service.
token: (none)
Public endpoints
- POSThttps://nova-captcha.nova-email.workers.dev/captcha/get
- POSThttps://nova-captcha.nova-email.workers.dev/captcha/verify
- GEThttps://nova-captcha.nova-email.workers.dev/widget.js
Embed it
<script src="https://nova-captcha.nova-email.workers.dev/widget.js" async></script> <div class="nova-captcha" data-theme="dark" data-callback="onHuman"></div>
Add data-difficulty or data-mode="invisible" as needed, then verify every token server-side with POST /captcha/verify.
NOVA Captcha protects NOVA Mail's signup, login, and disposable-address flows. It handles millions of challenges without a single tracking script.