HelloCaptcha provides its CAPTCHAs via a web service. It means that CAPTCHAs are generated on the HelloCaptcha server and passed back to the partner's web server. The partner builds the received CAPTCHA into the form that needs bot checking and sends it to the browser of the website visitor. When the visitor fills in the form including the answer to the CAPTCHA and posts it, the partner can ask the HelloCaptcha server whether the answer was right or not.