The present invention relates to isolated polypeptides having xylanase activity, catalytic domains, carbohydrate binding modules and polynucleotides encoding the polypeptides, catalytic domains or carbohydrate binding modules. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains or carbohydrate binding modules.