Shield
Edge Shield
A lightweight CAPTCHA alternative. Shield verifies visitors invisibly — no puzzles, no cookies, no tracking — and returns a 1–100 humanity score your application can act on. Free forever, with unlimited verifications.
Key Features
Invisible Verification
A proof-of-work challenge solved in a background thread. Real visitors almost never see anything — and never label traffic lights.
Humanity Score
Every verification carries a 1–100 score — 1 is confirmed automation, 100 a confirmed human. Allow, step up, redirect, or block on your own thresholds.
Privacy by Architecture
No cookies, no fingerprint database, no per-visitor storage. Only hourly aggregate counters are kept — GDPR and CCPA friendly by default.
Turnstile-Compatible
The siteverify response matches Cloudflare Turnstile's exactly, plus the score. Migrating is a URL and key swap.
How It Works
The widget requests a challenge
A cryptographically signed challenge is issued by the Shield service. Difficulty adapts to risk signals — clean browsers get trivial work.
The browser solves it invisibly
A SHA-256 proof-of-work runs in a Web Worker — tens of milliseconds on a phone, with no impact on your Core Web Vitals.
A response token is minted
The solution plus coarse environment signals produce a signed, single-use token containing the humanity score. It's added to your form automatically.
Your server validates the token
One POST to siteverify with your secret key returns the verdict, hostname, and score. Tokens expire after 5 minutes and can be used exactly once.
Pricing
Shield's core protection is free forever — unlimited widgets, unlimited verifications, all three widget modes, and the humanity score included. There are no monthly assessment caps and no credit card required.