GPX (Guitar Pro 6 Document) is a special container file format developed by Arobas Music for storing musical scores and guitar or bass tablatures created with their multitrack editor Guitar Pro.

The Guitar Pro 6 GPX file is strictly a file containing musical notation. Contrary to older Guitar Pro formats, such as GP3, GP4 and GP5, data stored in GPX files is encoded using a proprietary made dynamic dictionary compression scheme.

The data itself, once uncompressed, represents a �"little hard-disk” (an independent file system) consisting of various XML files that contain the actual data used for rendering the file inside the Guitar Pro editor, such as information about the various bars, tracks, voices, beats and notes that form the actual file.

On its own a GPX file contains no real audio data, but only metadata used for generating audio with the Guitar Pro editor.

A major downside of GPX files is that they cannot be natively exported to one of the older Guitar Pro formats, making it impossible to open Guitar Pro 6 documents, without buying the latest copy of Guitar Pro.

GPX files can still be exported to MIDI and thus imported to an older version of the editor, however that usually renders inaccurate tablatures, making it a less-than-ideal solution.