“Green Light” is about Lorde’s first major heartbreak and is “the first chapter of the last two wild, fluorescent years” of Lorde’s life before the song dropped. Over those years, 2015 to 2017, Lorde became an adult and moved away from her “glossy idiot god” teenage-self and “crossed over” to adulthood. In a Facebook post on her 20th birthday, she described 2016 as a “colossal year.”

The song was promoted heavily via the website “imwaitingforit.com” which released teasers of the music video for the track for three days before it officially dropped. One day before the website’s launch, the first teaser was aired as a commercial across New Zealand, Lorde’s home country, and two days before the song dropped, she left clues around specific locations in Auckland, New Zealand, containing lyrics from the song and hints about its title.

It is Lorde’s first solo release since her 2013 debut album Pure Heroine, and since her curation of The Hunger Games: Mockingjay soundtrack. The single’s artwork was painted by Sam McKinniss.