<!doctype html><htmllang=en-us><head><metacharset=utf-8><metahttp-equiv=x-ua-compatiblecontent="ie=edge"><metaname=viewportcontent="width=device-width,initial-scale=1,shrink-to-fit=no"><linkrel=preloadas=fonthref=/fonts/vendor/jost/jost-v4-latin-regular.woff2type=font/woff2crossorigin><linkrel=preloadas=fonthref=/fonts/vendor/jost/jost-v4-latin-700.woff2type=font/woff2crossorigin><linkrel=stylesheethref=/main.499b994519858c1434b91f11437691401e5c08a553d2187e8f7accfadbee2b0321c33192a4c63dd24fdeee64f99eb025f338561b35e72c340dfb249788196c20.cssintegrity="sha512-SZuZRRmFjBQ0uR8RQ3aRQB5cCKVT0hh+j3rM+tvuKwMhwzGSpMY90k/e7mT5nrAl8zhWGzXnLDQN+ySXiBlsIA=="crossorigin=anonymous><noscript><style>img.lazyload{display:none}</style></noscript><metaname=robotscontent="index, follow"><metaname=googlebotcontent="index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1"><metaname=bingbotcontent="index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1"><title>mCaptcha - mCaptcha</title><metaname=descriptioncontent="mCaptcha is proof-of-work based captcha system that is privacy focussed and fully automated."><linkrel=canonicalhref=/><metaname=twitter:cardcontent="summary_large_image"><metaname=twitter:imagecontent="//static/images/landing.jpg"><metaname=twitter:titlecontent="Defend Like Castles"><metaname=twitter:descriptioncontent="mCaptcha is proof-of-work based captcha system that is privacy focussed and fully automated."><metaname=twitter:sitecontent="@"><metaname=twitter:creatorcontent="@"><metaproperty="og:title"content="Defend Like Castles"><metaproperty="og:description"content="mCaptcha is proof-of-work based captcha system that is privacy focussed and fully automated."><metaproperty="og:type"content="website"><metaproperty="og:url"content="/"><metaproperty="og:image"content="//static/images/landing.jpg"><metaproperty="og:updated_time"content="2021-03-09T18:56:02+05:30"><metaproperty="og:site_name"content="mCaptcha"><metaproperty="article:publisher"content="https://www.facebook.com/"><metaproperty="article:author"content="https://www.facebook.com/"><metaproperty="og:locale"content="en_US"><linkrel=alternatetype=application/rss+xmlhref=/index.xml><scripttype=application/ld+json>{"@context":"http://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"\/"}]}</script><metaname=theme-colorcontent="#fff"><linkrel=apple-touch-iconsizes=180x180href=/apple-touch-icon.png><linkrel=icontype=image/pngsizes=32x32href=/favicon-32x32.png><linkrel=icontype=image/pngsizes=16x16href=/favicon-16x16.png><linkrel=manifesthref=/site.webmanifest></head><bodyclass=home><divclass="header-bar fixed-top"></div><headerclass="navbar fixed-top navbar-expand-md navbar-light"><divclass=container><inputclass="menu-btn order-0"type=checkboxid=menu-btn>
<aclass="btn btn-primary btn-lg px-4 mb-2"href=/docs/prologue/introduction/role=button>Get started</a><pclass=meta>Libre software <ahref=https://github.com/mCaptcha>GitHub</a></p></div></div></section></div></div><sectionclass="section section-sm"><divclass=container><divclass="row justify-content-center text-center"><divclass=col-lg-5><h2class=h4>Privacy focused</h2><p>Doesn't track, doesn't profile your users.</p></div><divclass=col-lg-5><h2class=h4>Robust and Accurate</h2><p>Got users behind <ahref=https://en.wikipedia.org/wiki/Network_address_translation>NATs</a>? No issues. We don't use IP address for rate-liming. NAT or not you get the mCaptcha experience.</div><divclass=col-lg-5><h2class=h4>Best-in-class UX</h2><p>mCaptcha is silent, so silent that your users won't even feel it. No more annoying images, no more helping for Big Brothers with their ML stuff</p></div></div><divclass="row justify-content-center text-center"><divclass=col-lg-5><h2class=h4>Defend like castles</h2><p>Our <ahref=https://en.wikipedia.org/wiki/Proof_of_work>PoW</a>-based solution defends fiersly. mCaptcha makes attacking your site more experience than what it will take for you to respond to the attacker's requests</p></div><divclass=col-lg-5><h2class=h4>Libre Software</h2><p>Client libraries are licensed using properiatary-friendly free software licenses but the core is <ahref=http://www.gnu.org/licenses/agpl-3.0>AGPL'd</a>. We believe this is a tech that can change the way the web works so mCaptcha will always be free</p></div><divclass=col-lg-5><h2class=h4>xCaptcha drop-in replacement</h2><p>Already using a captcha solution? No worries, our APIs are compatible with reCaptcha and hCaptcha!</p></div></div></div></section><sectionclass="section section-sm container-fluid"><divclass="row justify-content-center text-center"><divclass=col-lg-9></div></div></section><footerclass="footer text-muted"><divclass=container><divclass=row><divclass="col-lg-8 order-last order-lg-first"><ulclass=list-inline><liclass=list-inline-item>Powered by <ahref=https://gohugo.io/>Hugo</a>, and <ahref=https://getdoks.org/>Doks</a></li></ul></div><divclass="col-lg-8 order-first order-lg-last text-lg-end"><ulclass=list-inline><liclass=list-inline-item><ahref=/about/>About</a></li><liclass=list-inline-item><ahref=/donate>Donate</a></li><liclass=list-inline-item><ahref=/privacy-policy/>Privacy</a></li><liclass=list-inline-item><ahref=/security>Security</a></li><liclass=list-inline-item><ahref=https://stats.uptimerobot.com/GK7VLFJnBl>Status</a></li><liclass=list-inline-item><ahref=/thanks>Thanks</a></li></ul></div></div></div></footer><scriptsrc=/main.min.db67f0caa6a5788b691b9509981d6e5943f4b8d829170a674f468d4b23671ce4017c47a0a22116a8fc2f2de556c8b48f1afecd86707066f2f022c5dd83e8ea3c.jsintegrity="sha512-22fwyqaleItpG5UJmB1uWUP0uNgpFwpnT0aNSyNnHOQBfEegoiEWqPwvLeVWyLSPGv7NhnBwZvLwIsXdg+jqPA=="crossorigin=anonymousdefer></script><scriptsrc=/index.min.14d90a1bf5eef7d2b17902afe7b9ef7f8050a0619390568503a8254f864e31029e63bec047cd6efd6d23a2470d3458899332e923065cef88508028b49ab0b873.jsintegrity="sha512-FNkKG/Xu99KxeQKv57nvf4BQoGGTkFaFA6glT4ZOMQKeY77AR81u/W0jokcNNFiJkzLpIwZc74hQgCi0mrC4cw=="crossorigin=anonymousdefer></script></body></html>
