In one example, a computing system comprises processing circuitry that executes instructions to determine whether a media content item is eligible for identification of key moments, retrieve a plurality of reactions associated with the media content item, wherein each reaction comprises a reaction timestamp that corresponds to a time at which a reaction was received and a graphical icon that corresponds to one of the reactions, group the reactions based on the reaction timestamp and the selected graphical icon, identify a plurality of key moments within the media content item based on the groupings, wherein each of the key moments is associated with a representative graphical icon that corresponds to an aggregated viewer reaction, and cause an indication of the media content item to be presented in a user interface while presenting the aggregated viewer reaction at each time window associated with each of the key moments.