The song reached number one in Ireland and New Zealand as well as peaking within the top ten in Australia, Canada, United Kingdom and United States. It also reached the top forty in countries like Denmark, Germany and Switzerland. The accompanying music video features Brown in several scenes pursuing his love interest. The video features much dancing and digital effects. The official remix features Lil Wayne and Lupe Fiasco.
The song was written by Brown and his songwriting team, the Graffiti Artists (Rob Allen and Andre Merritt). He stated that after entering the studio, Polow da Don created a beat that Brown wrote along to. Because the producer's style was "more of a European, techno, house-type feel," the group "wanted to give it that other side of crossover, and go a little bit to that pop realm". "Forever" is one of four new songs Brown recorded for the re-release of his second studio album Exclusive. He recorded the song using an autotune effect, as he did in one of his previous singles, "Kiss Kiss". The song was first intended to be on Brown's following album, but decided he "wasn't ready to release a new album yet".
"Forever" is actually an extended version of a commercial jingle for Doublemint gum, commissioned by an advertising company working for Wrigley. Brown first created the short version for the commercial, then extended and amended it into a full song during a recording session in February 2007, which was paid for by the gum company. Originally, the plan was to follow up his third single, "With You," with the Kanye West-featuring "Down," but the new material won out. Although the label initially was reluctant to release "Forever" as a single, the song was so "potent and strong" that it overruled any hesitations regarding its commercial connections.
The song was first released in on November 2, 2007 as a digital download in Australia, Austria, Belgium, Canada, Denmark, France, New Zealand. The digital download release for the song came months later on April 15, 2008 in France, on April 22, 2008 in Japan and on August 12, 2008 in the United States and the Netherlands. An EP featuring three remixes was released in Ireland on June 13, 2008, in Australia, Austria and the Netherlands on June 16, 2008 and in Japan on August 13, 2008.
"Forever" is a Eurodance and Euro disco song that runs for 4:38 (4 minutes and 38 seconds). It contains influences of techno, trance, and house boasting bubbling and gurgling synths and a "rolling around the bottom of the sea"-sounding bass line. According to the digital sheet music published at Musicnotes.com by EMI Music Publishing, it is written in the key of B major, with a simple chord progression of E-B-F#-C#m. The song runs through a "with movement"-style tempo and maintains a tempo of 120 beats per minute in common time. Brown's vocal range spans nearly an octave and a half from B3 to G#5.