"3am" is a "honey-voiced" heartfelt ballad that serves as a drunk dialing come-on, which later becomes a regret. While most of Title portrays Trainor as confident, "3am" is afflicted with insecurity, and its lyrics imply that she succumbs to an ex-boyfriend despite her independent woman morale. According to Marc Hirsh of The Boston Globe, "3am" is a "quieter and more vulnerable, racked with self-doubt that can't just be sung away with a good pep talk in the mirror". Piet Levy of the Milwaukee Journal Sentinel opined that the track was "a rare departure into serious, sad territory" for Trainor. The track's sound features a shift from the album's throwback influence to a more R&B influence, and includes a snippet of a phone being dialled at the beginning and end of its duration.