He is best known as the lead guitarist in the metal bands The Haunted and At the Gates, alongside his bass-playing twin brother Jonas Björler.

In July 1996, at the end of the touring cycle for their critically acclaimed 1995 album Slaughter of the Soul, Björler left the band and At the Gates consequently split up.

In October 2007, At the Gates announced a final reunion for 2008, playing major European music festivals and tour dates in the US, Japan and Sweden.

[4] Björler's debut album 'Antikythera' was released by Anders Fridén (In Flames) on his label Razzia Notes Records in November 2013.

[5] It focuses on Björler's love for Italian movie soundtracks from the 1960s–80s, but also contains elements of English progressive rock, jazz, post-rock and Swedish folk music.