ReCaptcha Contcat Form 7


ReCaptcha Mining CF7 protects your "Contact Forms 7"-forms against spam and brute-force attacks. You can get it here:


No input is required from your visitor
Still receive 100 percent of the real requests!
Compliant to GDPR (respectively DSGVO, RGPD) and no data tracking
No external ressources
Easy to use: Install, activate, insert hook [rcm_cf7] into your CF7 forms
Only necessary code (40 KBytes webspace)
Works optionally with the plugin "flamingo"
No ads
Security and performance can be further optimized to personal requirements

How it works

The plugin is based upon a mining-approach that we know from several crypto-currencies:

The client-browser has to spend a little computation effort in order to solve a hash-based puzzle. When the form is submitted and the puzzle is not solved, or it is not solved correctly, the server recognizes the request as spam.

What is about the computation effort? Your visitors won't even recognize the very short computation effort, even if they use mobile devices with comparatively low computing power. Spam-bots typically request thousands of webpages within seconds. For them even little computation efforts for many pages sum up. Therefore spam bots avoid computations by either submitting forms directly after the HTML is loaded completely, or they just close the respective connections whithout submission, if longer computation is required.

As bots from web-crawlers (i.e. Googlebot) act very similar to spam-bots, they face the same problems. Therefore they will penalize computation efforts with a bad ranking. But as web-crawlers usualy do not submit forms on your webpage, they can easily be distinguished. The plugin does so, by starting to generate the puzzle not sooner, as when the user has pressed a key the first time. Whereas webcrawlers won't press any keys, spam-bots usually do so in order to mimic human behaviour.