Privacy-first spam protection with an interactive slider challenge. No tracking, no cookies, no external services. GDPR compliant by design.

Opportify

Opportify Fraud Protection

Stop fake leads, form spam, and bot registrations before they reach your database. AI-powered fraud scoring across 100+ signals. No CAPTCHA required.

solariane

<p><strong>Stop spam without collecting visitor data.</strong></p>
<p>SOS Captcha protects your WordPress forms with an interactive slider challenge. Visitors drag a handle along a track to prove they are human. The plugin runs entirely on your own server — no tracking, no cookies, no external services.</p>
<h3>Privacy by design</h3>
<ul>
<li>No tracking pixels or analytics</li>
<li>No cookies stored</li>
<li>No data sent to external services</li>
<li>GDPR, CCPA, and ePrivacy friendly</li>
<li>All validation happens on your server</li>
</ul>
<h3>Visitor-friendly slider</h3>
<ul>
<li>Touch-friendly interaction works on mobile</li>
<li>Most visitors complete it in a few seconds</li>
<li>Smooth animation on success</li>
</ul>
<h3>How the protection works</h3>
<ul>
<li>Unique cryptographic tokens per session</li>
<li>Random checkpoint positions (up to 8 in Free, 15 in Premium)</li>
<li>Server-side timing validation</li>
<li>Rate limiting (configurable, 60s default)</li>
<li>Behavioral analysis (Premium)</li>
<li>Honeypot fields and browser fingerprinting (Premium)</li>
</ul>
<h3>Form integrations</h3>
<ul>
<li>Contact Form 7 (Free)</li>
<li>WordPress Comments (Free)</li>
<li>WPForms (Premium)</li>
<li>Gravity Forms (Premium)</li>
<li>Ninja Forms (Premium)</li>
<li>WooCommerce checkout, registration & reviews (Premium)</li>
</ul>
<h3>Authentication form protection (Premium)</h3>
<ul>
<li>WordPress login form (<code>wp-login.php</code>) — protect against brute-force attacks</li>
<li>User registration form — prevent bot-generated accounts</li>
<li>Lost-password form — block password-reset email spam</li>
</ul>
<h3>How it works</h3>
<p>SOS presents a slider with randomly positioned checkpoints. Visitors slide a cursor along the track to activate each checkpoint in sequence. Each session generates unique cryptographic tokens with millions of possible combinations and server-side timing validation. Premium plans add behavioral analysis on top.</p>
<h3>Free vs Premium</h3>
<p><strong>Free version includes:</strong></p>
<ul>
<li>Unlimited forms and submissions</li>
<li>Contact Form 7 integration</li>
<li>WordPress comments protection</li>
<li>Customizable appearance (colors, text)</li>
<li>Up to 8 checkpoints per challenge</li>
<li>Full GDPR compliance</li>
<li>Community support</li>
</ul>
<p><strong>Premium features:</strong></p>
<ul>
<li>WPForms, Gravity Forms, Ninja Forms integrations</li>
<li>WooCommerce protection (checkout, registration, reviews)</li>
<li>WordPress login, registration, and lost-password protection</li>
<li>Advanced behavioral detection</li>
<li>Browser fingerprinting</li>
<li>Honeypot fields</li>
<li>Local statistics dashboard (privacy-first, no data leaves your server)</li>
<li>Priority email support</li>
<li>White-label (remove badge)</li>
<li>Up to 15 checkpoints per challenge</li>
</ul>
<p><a href="https://sos-captcha.com/#pricing" rel="nofollow ugc">Upgrade to Premium</a> — from €4.99/month or €47/year.</p>
<h3>Technical Highlights</h3>
<ul>
<li><strong>Cryptographic security:</strong> Unique tokens per session with server-side validation</li>
<li><strong>No database bloat:</strong> Uses WordPress transients (auto-cleanup)</li>
<li><strong>Lightweight:</strong> Under 20KB total assets</li>
<li><strong>Performance:</strong> Cached responses, minimal server load</li>
<li><strong>Developer-friendly:</strong> Hooks and filters for customization</li>
<li><strong>Translation-ready:</strong> 10 languages included (EN, FR, DE, ES, IT, PT-BR, AR, JA, ZH, HI)</li>
</ul>
<h3>Compliance</h3>
<ul>
<li>GDPR Article 25 (Privacy by Design)</li>
<li>CCPA compliant (no personal data collection)</li>
<li>ePrivacy Directive compliant (no cookies)</li>
</ul>
<h3>Support & Documentation</h3>
<ul>
<li>Documentation at https://sos-captcha.com</li>
<li>Community forum (Free)</li>
<li>Email support (Premium)</li>
<li>French and English support</li>
</ul>
<h3>Source Code</h3>
<p>The plugin ZIP ships both the human-readable source (<code>assets/challenge-slider.js</code>, <code>admin/js/sos-admin.js</code>, <code>assets/*.css</code>, <code>admin/css/*.css</code>) and the minified production builds (<code>.min.js</code>, <code>.min.css</code>). WordPress loads the minified versions in production and the source versions when <code>SCRIPT_DEBUG</code> is enabled (<code>define('SCRIPT_DEBUG', true)</code> in <code>wp-config.php</code>).</p>
<h3>Privacy Policy</h3>
<p>SOS Captcha is designed with privacy at its core:</p>
<p><strong>Data collection:</strong> None. We don’t collect, store, or transmit any personal data to external servers.</p>
<p><strong>Cookies:</strong> None. The plugin sets no cookies.</p>
<p><strong>External services:</strong> None. All processing happens on your WordPress server.</p>
<p><strong>IP addresses:</strong> Not stored. Rate limiting uses transient hashes that auto-expire.</p>
<p><strong>Statistics (Premium):</strong> Stored locally on your server only. Aggregated counters (blocked spam, form types) with no personally identifiable information.</p>
<p><strong>Licensing (Premium only):</strong> When you activate a Premium license, your site URL and license key are sent to https://sos-captcha.com to validate the license. No user data is transmitted.</p>
<h3>Hooks for Developers</h3>
<ul>
<li><code>sos_before_validation</code> — Modify validation parameters</li>
<li><code>sos_challenge_created</code> — React to new challenges</li>
<li><code>sos_spam_blocked</code> — Trigger actions when spam is blocked</li>
<li><code>sos_should_show_badge</code> — Control badge visibility</li>
</ul>


Alternatives to SOS Captcha — Privacy-First Spam Protection

Top alternatives