Popular online platforms among UPSC aspirants for study materials include BYJU'S, Unacademy, and Drishti IAS. These platforms offer a variety of video lectures, test series, and study resources tailored for exam requirements. They often feature experienced educators who provide insights into complex topics and exam strategies. Additionally, aspirants frequently utilize social media groups and forums for peer interactions and shared resources. These platforms facilitate a collaborative learning environment, helping aspirants access diverse materials and stay motivated throughout their preparation journey.