"Heartlines" is a song recorded by New Zealand music duo Broods from their second studio album, Conscious (2016). Georgia Nott and Caleb Nott, the sole members of Broods, wrote the song with New Zealand singer Lorde and record producer Joel Little, who was responsible for production. It was first released on 10 June 2016 as the first promotional single from the album, and later as the album's second single on 16 January 2017. It is a synthpop track with electronic beats and synthesizers. Its lyrics detail the hope left in a tumultuous long-distance relationship.