This paper deals with penetration testing, a key method for assessing the security of information systems and web applications. The introduction discusses the history of web security and the rise of the need for penetration testing, emphasizing the necessity of its application in today’s digital environment. Penetration testing enables the identification of vulnerabilities within web applications and information systems that attackers could exploit to compromise the systems. Furthermore, the paper analyzes the penetration testing process, including methods, challenges, and approaches such as Black box, White box, and Gray box testing. A review and comparison of tools used in penetration testing provides deeper insight into their advantages and disadvantages, as well as describing their necessity and role in the overall penetration testing process. The practical part of the paper includes an example of a real-world penetration testing, demonstrating specific steps and analyzing the results. The conclusion emphasizes the importance of penetration testing as an indispensable part of an information security strategy and the need for ongoing improvement in this field.