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Free — 10,000 Challenges/Month

CAPTCHA asks if you're human.
BotShield asks you to prove it.

One script tag. Zero tracking. Zero third-party data. Your visitor's browser solves a cryptographic challenge invisibly — no images, no checkboxes, no Google. Difficulty auto-scales to stop bots while remaining invisible to real visitors.

Add to Your Site Get Your API Key
0
Images to solve
0
Bytes of tracking data
1–3s
Invisible solve time
10K/mo
Free challenges
The Problem

Every existing solution punishes your users to stop bots

CAPTCHAs, tracking scripts, and rate limiters all extract a cost from legitimate visitors. BotShield extracts the cost from the attacker instead.

👁

reCAPTCHA Is Google's Data Collection Tool

Google collects behavioral data across every site using reCAPTCHA. Your visitors are the product. GDPR liability every time the widget loads. A tracking pixel disguised as security.

🚫

CAPTCHAs Are Hostile UX

Visual puzzles block screen readers, frustrate mobile users, and add 10–30 seconds of friction. Accessibility lawsuits are increasing year over year. Your conversion rate drops with every puzzle.

🚧

Rate Limiting Punishes Real Users

VPNs, corporate networks, and mobile carriers share IPs. Rate limiting blocks legitimate users while sophisticated bots rotate IPs freely. You're blocking the wrong people.

How It Works

Cryptographic proof of work. Invisible to humans. Expensive for bots.

BotShield shifts the cost from the user to the attacker. Every visitor's browser solves a small math problem. At scale, bots can't afford it.

Step 1
Challenge
Server issues a random nonce + difficulty level. Signed with post-quantum Dilithium so challenges are unforgeable and cannot be replayed.
Dilithium-signed
Step 2
Prove
Browser solves SHA-256 proof of work using the Web Crypto API. Runs in a Web Worker. Non-blocking. The user never sees it.
1–3 seconds
Step 3
Verify
Server checks the solution in microseconds. Verifies nonce freshness, difficulty target, and Dilithium signature. Issues session token.
µs verification
Step 4
Protected
Every subsequent request carries the session token. No re-challenge until the session expires after 1 hour. Protected. Silent. Done..
1-hour session
Integration

Three paths. Pick the one that fits.

From a single script tag to full API control. BotShield works with any stack, any framework, any language.

Path 1
One Script Tag
Drop this into your HTML. BotShield automatically protects all forms on the page. No backend changes required.
index.html
<!-- Add before </head> -->
<script src="https://api.h33.ai/v1/botshield/script.js"></script>
Path 2
API Integration
Full control over when challenges are issued. Frontend requests a challenge, solves it, sends the token to your backend for verification.
frontend.js
// Request challenge from H33
const challenge = await fetch('https://api.h33.ai/v1/botshield/challenge', {
  method: 'POST',
  headers: { 'X-API-Key': 'your_api_key' },
}).then(r => r.json());

// Solve proof of work in Web Worker
const solution = await solveChallenge(challenge.nonce, challenge.difficulty);

// Send solution + form data to your backend
await fetch('/api/submit', {
  method: 'POST',
  body: JSON.stringify({ solution, ...formData }),
});
backend.py
import requests

def verify_botshield(solution: str) -> bool:
    """Verify proof-of-work solution with H33 API."""
    resp = requests.post(
        "https://api.h33.ai/v1/botshield/verify",
        json={"solution": solution},
        headers={"X-API-Key": "your_api_key"},
    )
    return resp.json()["valid"]
Path 3
Rust Middleware
Tower-compatible middleware for Axum, Actix, or any Rust HTTP framework. Automatic challenge/verify on every request.
main.rs
use h33_botshield::{BotShieldLayer, Difficulty};

let app = Router::new()
    .route("/api/submit", post(handler))
    .layer(
        BotShieldLayer::new("your_api_key")
            .difficulty(Difficulty::Adaptive)
            .session_ttl(Duration::from_secs(3600))
    );
Comparison

How BotShield compares

Every other solution trades your users' privacy or patience for bot protection. BotShield trades math.

reCAPTCHA hCaptcha Turnstile BotShield
Tracking Extensive behavioral tracking Privacy-focused, some data Cloudflare telemetry Zero. No personal data.
User friction Image puzzles, 10-30s Image puzzles, 10-30s Invisible, occasional fallback Invisible. Always. 1-3s.
Accessibility Screen reader hostile Screen reader hostile Mostly accessible Fully accessible. No UI.
Third-party dependency Google infrastructure hCaptcha infrastructure Cloudflare infrastructure Self-contained. One API call.
GDPR compliant Requires consent banner Improved, still collects data Cloudflare DPA required By architecture. No PII.
Cost Free (you pay with user data) Free tier + paid Free (Cloudflare lock-in) 10K/mo free. $49/mo unlimited.
Adaptive Difficulty

Difficulty scales with threat level. Humans never notice.

BotShield monitors request patterns in real time. Normal visitors get a trivial challenge. Suspicious traffic faces exponentially harder proof of work. The cost is always on the attacker.

Normal
16 bits

1–3 seconds

Default for all visitors. The browser finds a SHA-256 hash with 16 leading zero bits. Completely invisible. Runs in a Web Worker. The user never knows it happened.

Elevated
20 bits

10–30 seconds

Triggered by repeated requests from the same session or IP pattern. Slows scrapers and credential stuffing tools to a crawl. Human visitors in this bracket see a brief "verifying" message.

Maximum
24 bits

Minutes

Reserved for confirmed bot signatures and volumetric attacks. Makes automated abuse economically unviable. A bot farm spending GPU cycles on proof of work is a bot farm not attacking you.

No CAPTCHAs. No tracking. Just math.

0 PII
Data collected
µs
Server verification
1 tag
To integrate
Secured by H33.ai

The badge your visitors trust

The "Secured by H33.ai" badge tells visitors your site uses cryptographic bot prevention instead of invasive tracking. It means no CAPTCHA, no behavioral profiling, no third-party data collection.

H
Secured by H33.ai
Pricing

Free to start. Simple to scale.

Start protecting your site today. No credit card required for the free tier. Upgrade when you need more.

Free
$0
forever
Perfect for personal sites, side projects, and small businesses. Full protection, no cost.
  • 10,000 challenges per month
  • Adaptive difficulty
  • SHA-256 proof of work
  • Dilithium-signed challenges
  • 1-hour session tokens
  • Web Crypto API integration
  • "Secured by H33.ai" badge displayed
  • Custom difficulty settings
  • Webhooks
  • Analytics dashboard
Get Started Free
FAQ

Frequently asked questions

How does BotShield work without CAPTCHA?

BotShield uses cryptographic proof of work instead of visual puzzles. When a visitor loads your page, their browser receives a random nonce and difficulty level from the H33 API. The browser then uses the Web Crypto API to find a SHA-256 hash that meets the difficulty target. This takes 1–3 seconds for a normal browser and is completely invisible to the user. No images, no checkboxes, no puzzles. The server verifies the solution in microseconds and issues a session token valid for 1 hour.

Does BotShield track my users?

No. BotShield processes zero personal data. No cookies are set for tracking purposes. No behavioral data is collected. No fingerprinting occurs. The only data transmitted is the cryptographic challenge and its solution. There is no user profile, no cross-site tracking, and no data shared with any third party including H33. Your visitors remain completely anonymous.

Is BotShield GDPR compliant?

Yes, by architecture rather than by policy. BotShield does not process any personal data as defined by GDPR Article 4. No IP addresses are stored, no behavioral profiles are created, no cookies are used for tracking, and no data is shared with third parties. Because no personal data is processed, no consent banner is required for BotShield specifically. This is compliance through engineering, not through legal paperwork.

How long does the challenge take?

At the default difficulty level (16 bits), the challenge takes 1–3 seconds on a modern browser. The computation runs in a Web Worker so it does not block the main thread or affect page responsiveness. The user never sees any indication that a challenge is being solved. If elevated difficulty is triggered due to suspicious patterns, the challenge may take 10–30 seconds, which naturally rate-limits automated tools.

What about mobile users?

BotShield works on all modern browsers including iOS Safari, Chrome for Android, and Firefox Mobile. The Web Crypto API is supported on all major mobile browsers. Challenge difficulty automatically adjusts based on the client's reported capabilities, ensuring mobile users are not penalized for lower compute power. Typical solve times on mobile are 2–4 seconds at normal difficulty.

Can bots solve the challenge?

Yes, any computer can solve a SHA-256 proof-of-work challenge. That is by design. The protection comes from the cost: at scale, solving thousands of challenges per minute requires significant compute resources that cost real money. A single human visitor solves one challenge in 1–3 seconds and gets a 1-hour session token. A bot farm trying to generate 10,000 sessions faces exponentially harder challenges as BotShield's adaptive difficulty kicks in, making the attack economically unviable.

How do I remove the badge?

The "Secured by H33.ai" badge is displayed on the free tier as attribution. Upgrading to the Pro plan at $49 per month removes the badge requirement and gives you unlimited challenges, custom difficulty settings, webhooks, and analytics. You can upgrade at any time from the H33 dashboard.

Does BotShield work with WordPress?

Yes. Add the single script tag to your WordPress theme header (Appearance > Theme Editor > header.php) or use a plugin like Insert Headers and Footers. BotShield automatically protects all forms on the page. No WordPress-specific configuration is needed. It also works with WooCommerce checkout, Contact Form 7, Gravity Forms, and any other form plugin.

Add BotShield to your site in 10 seconds

One line of HTML. No backend changes. No signup friction. Start protecting your site right now.

<script src="https://api.h33.ai/v1/botshield/script.js"></script>

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