The album, which has an approximate duration of 41 minutes, stands out for songs like Warning, which gives the album its title, and Minority. The latter, in particular, became a benchmark for its energy and message. Billie Joe Armstrong, the vocalist and guitarist, was greatly inspired by the musical experimentation and socially conscious lyrics of Bob Dylan's 1965 album Bringing It All Back Home. Despite the album presenting a stylistic change that generated divided opinions, critics recognized the quality of Armstrong's songwriting. While it reached number four on the US Billboard 200, Warning represented a dip in commercial sales for Green Day compared to their previous works on major record labels. It is estimated to have sold over 1.2 million copies in the United States and 3.5 million worldwide.
The band had gone through a period of rest after the promotion of Insomniac (1995) and then embarked on a tour for Nimrod that included more intimate shows. By the time Warning was being prepared, the mainstream music landscape had changed, making way for genres like nu metal. Initially, Green Day considered working with Scott Litt, known for his work with bands like Nirvana and R.E.M., but the chemistry was not as expected. Finally, they returned with Rob Cavallo, but this time the band took on most of the production tasks. The sound of Warning, with its mix of pop-punk, power pop, and folk punk, demonstrated the group's ability to explore new facets, incorporating details like a harmonica with a The Beatles feel on "Hold On" or music hall influences from The Kinks on "Misery", without abandoning their energetic and melodic essence.