Online courses can complement traditional study materials for UPSC preparation by providing a structured and flexible learning environment. They offer access to expert lectures, interactive sessions, and updated content that aligns with the current exam syllabus. Additionally, online platforms often include practice quizzes and assignments that reinforce learning. The use of technology allows candidates to connect with peers through online forums, enhancing collaborative learning. Furthermore, online courses can be tailored to specific subjects or skill areas, enabling aspirants to focus on individual weaknesses while supplementing their traditional study methods.