"Cool" received generally positive reviews from music critics, being compared to Cyndi Lauper and Madonna songs from the 1980s. The media have drawn parallels between the song's lyrical content and the romantic relationship that Stefani had with Tony Kanal, a fellow band member of No Doubt. "Cool" was moderately successful on the charts around the world, peaking within the top-ten in Australia, the Netherlands, the Czech Republic and New Zealand, as well as the top 20 in Denmark, Ireland, Norway, the United Kingdom and the United States.