The Internet nowadays is playing a significant role in our everyday life. Many web services have registration and require user input. These involve completely automated public Turing tests to tell computers and humans apart (CAPTCHA). The web services like Gmail registration, bank transactions, and ticket booking often face attacks from bots which are computer programs. The CAPTCHA is used to protect the sites from these dangerous bots. This technique offers good security for websites as analysis proves that humans can easily solve the CAPTCHA but bots can rarely do that. This is because computers do not have the visual capacity and real understanding like humans. There are four types of methods in the development of CAPTCHA. They are CAPTCHA based on images, audio, video, and puzzles. Here the paper is focused on the development of Puzzle-based CAPTCHA. This implies the user needs to solve the puzzle to access the website. If the puzzle is not solved, the user can’t go forward as the site treats it as a bot and denies access. This is one of the efficient methods which made it easily possible for humans but hard for bots. It involves human intelligence and simple testing. Various puzzles are used as a CAPTCHA. This paper is based on the pattern recognition puzzle CAPTCHA. The basic idea is that the user needs to identify the next pattern based on existing patterns. This involves simple logic which humans can solve. The pattern recognition puzzle challenges human intelligence and is much more difficult for the bots to solve so that it could be more secure.