A system for customizing media presentation based on user's sentiments is disclosed. The system presents a media item to the user on a platform comprising a website. The system captures a first set of microexpressions of the user reacting to the media item. The system extracts a set of baseline features from the first set of microexpressions. The system determines whether the media item elicits positive or sentiment from the user. If the system determines that the media item elicits positive sentiment from the user, the system classifies the media item into a first class of media items that elicit positive sentiment from the user. The system adjusts contents of the platform to include media items from the first class of media items.