The diversified sites and platforms have created new avenues for online teachers' professional development. Thus, the teachers find an alternative environment to solve the lack of teachers' professional development training programs. The current study aimed to evaluate the use of Web-Based Courses (WBCs) in the Microsoft Educator Community Platform (MECP) in teachers' professional development (TPD). It investigated the degree of teachers' satisfaction with WBCs and their challenges in learning through WBCs. A quantitative and qualitative research approaches were adopted to achieve the research objectives. The study sample consisted of (118) male and female teachers who were enrolled in the MECP and participated in completing a 5-point Likert scale survey. The sample also included ten teachers' trainers who the researcher interviewed. The findings of the study indicated a high degree of teachers' satisfaction with utilising WBCs in TPD. However, both teachers and trainers revealed that the English language of the courses' content was a challenge that hindered learning through WBCs. Many trainers' interviewees demonstrated their preference for online training more than face-to-face training, and that clear goals and content were effective online training elements. In light of research findings, the researcher affirmed the need to pay more attention to the use of WBCs in MECP for TPD and implications and recommendations for further research were proposed.