This extension will allow you to quickly and easily add a captcha to your customer account and affiliate registration processes, helping prevent bot and spam registrations on your site.
Upload and go — utilizes vQmod so no core file modifications are necessary.
Displays a proper error message when the captcha does not verify correctly.
For OpenCart 1.5 and 2.x versions, adds captcha verification for regular account registration, checkout account registration, and affiliate registration.
For OpenCart 2.x versions, properly uses Google reCAPTCHA like the rest of OpenCart.
For adding a captcha to account login areas, take a look at:
Login and write down your comment.
Login my OpenCart Account