Basketball court reservations are still predominantly made through conventional methods, such as phone calls, in-person visits, and private messages, which result in scheduling conflicts, double bookings, and inefficient administrative processes. This study aims to develop a web-based basketball court reservation information system to improve the efficiency of court management. This study uses the Research and Development (R&D) method with the Waterfall model, which includes requirements analysis, system design, implementation, testing, and maintenance. Data was collected through observation, structured interviews, and questionnaires. The system was developed using PHP, MySQL, HTML, CSS, and JavaScript, and is equipped with features for real-time schedule management, online booking, payment confirmation, and automated transaction reports. The results demonstrate that the website has high access speed, is responsive, and is stable for user use. Functional testing using the Black-Box Testing method showed that all system features operate as expected. After the Black-Box testing was completed, the web system was also tested for overall system speed. Based on Google PageSpeed Insights/Lighthouse testing, the web-based booking system demonstrated excellent and efficient performance across various devices. On mobile, the system achieved a performance score of 88%, an accessibility score of 93%, and a best practices score of 96%. On desktop, the system achieved a perfect performance score of 100%, with an accessibility score of 93% and a best practices score of 96%. Based on the test results, the web-based booking system was deemed highly suitable and received very positive feedback from both subject matter experts and end users. The subject matter experts’ validation of 20 indicators across eight aspects yielded an average score of 77 out of a maximum of 80, with a suitability percentage of 96.25%, which falls into the “Highly Suitable” category. Meanwhile, the results of the user response test, which involved managers and tenants, yielded an average score of 76.67 out of 80, with a 95.83% achievement rate, placing it in the “Highly Feasible” category. These results indicate that the system not only meets the criteria for technical and content validity but is also capable of providing benefits and effectively supporting operational activities and on-site booking processes.