Koffler was born in West Berlin, Federal Republic of Germany. He was raised with his three brothers in Charlottenburg by a working middle-class family. With the fall of the Berlin Wall, the Koffler family was severely affected, as Hanno's father fell professionally, forcing the family to move to Saxony-Anhalt. At an early age, Koffler began acting in small roles in plays.
In 1994 he founded the band "Kerosin" with his brother Max Koffler, Hanno being the drummer. The band ranked second in the world's largest live band contest "Emergenza" in 2002.
Upon returning to Berlin at the age of 18, Koffler applied for admission to the Ernst Busch Theater School, but was rejected. In 2002, he would officially begin his acting career with various roles in cinema films such as Anatomy 2 and in Marco Kreuzpaintner films, including the 2004 Summer Storm and Krabat in 2008. He later moved to Austria. to study acting until 2007 at the Max Reinhardt Seminar in Vienna, where he would play roles in various theatrical productions directed by Klaus Maria Brandauer.
After several performances in television, theater, and cinema, in 2013 he starred in the film Free Fall, along with Max Riemelt and Katharina Schüttler. The film was directed by Stephan Lacant and became a huge success both in Germany and internationally.
In 2019, he joined the original AmazonBeat series, again under the direction of Marco Kreuzpaintner, playing the character of Paul. That same year, he was part of the cast of the first season of German series, Pagan Peak.
