Pingback (callback) on

We provide a pingback (callback) option that allows you to get the answer for your captcha automatically when it's ready.
It allows you to get answers without making requests to and also allows you to avoid account suspension.

To receive automated pingback you have to:
Register your pingback domain/IP address.
Provide your pingback URL as a value for pingback parameter of your request to
Process HTTP POST request with URLencoded form data (application/x-www-form-urlencoded) coming from our server to your pingback URL. The request contains two parameters: id - captcha ID and code - the answer.

Incoming pingback request example:
You can use any pingback URL pointing to your registered domain/IP address so your URL can include custom parameters.
But there's one limitation: if you will submit your captcha with GET request and use URL that contains multiple parameters like then you will receive pingback to URL with only the first parameter ?myId=1. To avoid that use POST request with multipart/form-data.