NPZ is a file format by numpy that provides storage of array data using gzip compression. NpzFile is used to load files in the NumPy. use this in python3: from numpy import load data = load('out. The NPZ file type is primarily associated with nProtect by INCA Internet Co, Ltd. If you have a NPZ file that you need to open, but you're not sure how, follow these steps and open your NPZ file quickly and easily!.