CAPTCHA stands for Completely Automated Public Turing test to tell Computers and Humans Apart. As the acronym suggests, it is a test to determine whether the user is human or not. A typical CAPTCHA consists of distorted text, which a computer program will find difficult to interpret but a human can (hopefully) still read. Many websites use CAPTCHA to try and prevent bots from interacting with their website. For example, my bank website forces me to pass a CAPTCHA every time I log in, which is a pain. This chapter will cover how to solve a CAPTCHA automatically, first through Optical Character Recognition (OCR) and then with a CAPTCHA solving API.