After school he studied theatre.
He is known for his comedy-show Quatsch Comedy Club. During his childhood he lived in Nuremberg. In 1992, Hermanns started the comedy show Quatsch Comedy Club.
The show has been on German channel ProSieben since 1996.
In 2003 the show moved to the Theatre Friedrichstadtpalast in Berlin. Hermanns has written and produced different comedy shows on television, including Zapped (1998), Back to Life (2000) and Paranoid (2004) for Michael Mittermeier, Gayle Tufts and Cora Frost.
Hermanns was a director for Grease and Es fährt ein Zug nach Nirgendwo. Hermanns wrote for the television series Lukas (1997–1999), Meine beste Freundin (2000) with Mariele Millowitsch and Doris Kunstmann and for Sing, wenn du kannst! (2002) at the theatre Schmidts Tivoli in Hamburg.
Hermanns was television moderator of Red Nose Day and Popclub on channel ProSieben.
In May 2005 and 2006 Hermanns was moderator of Countdown Eurovision. He was also the moderator of the Vorentscheidung Eurovision Song Contest, and was spokesperson for this event from 2005 to 2008. Hermanns is openly gay and has been in a relationship for 14 years with Wolfgang Macht.