Snaptcha

Snaptcha is an invisible CAPTCHA that automatically validates forms and prevents spam bots from submitting to your Craft CMS site.

Snaptcha (Simple Non-obtrusive Automated Public Turing test to tell Computers and Humans Apart) will validate all POST requests to the front-end of your site, meaning that it will work with any form and any plugin. Note that since this will affect all POST requests, you must add the required template tag before enabling validation (see usage instructions).

With Snaptcha, we can see exactly what the user experiences when a submission is incorrectly marked as spam. A side-by-side comparison with the user-experience of ​“invisible” Recaptcha 3 can be seen here.