The use of web technologies has transformed the way businesses communicate with their clients, customers, and stakeholders. Although websites can be effective tools for sharing information, marketing, and public relations, people with disabilities and the elderly often face challenges when accessing information on websites. To address this issue, many countries have made web accessibility mandatory by law. This study aims to evaluate the web accessibility of the 100 largest Turkish companies, as ranked by Capital magazine, and to assess the usability, readability, and security of their corporate websites. Despite some areas for improvement, the study identified significant issues related to accessibility, usability, readability, and security. The report provides recommendations for developers and administrators on how to address these issues and ensure that information is accessible to all stakeholders. Ultimately, the study aims to help organizations and web developers improve their policies and practices to enhance web accessibility, usability, readability, and security.