GP3 is a file extension that is given by a specialized software tool called Guitar Pro 3. This program uses GP3 files to save documents containing tabs made in the string instrument program. GP3 files also contain the typical musical notation for a staff.

GP3 files can contain a record for one instrument or the entire score written for several different instruments. Although the data in GP3 files is not audio data, the program can use it to play the composition using MIDI. GP3 files can be easily printed.