Garmin MapSource (.gdb, .mps)

GDB and MPS are the file formats of Garmin MapSource, the desktop mapping and route-planning program that came with Garmin devices for years. If you have an old Garmin archive, this is probably what it is in.

At a glance

Extension .gdb, .mps
Encoding binary
By Garmin

History

MapSource was Garmin's Windows desktop software for browsing map products, planning routes and exchanging data with a connected device. MPS is the file format of the MapSource 5.x generation; GDB, the "Garmin database" format, replaced it from MapSource 6.x onwards. Garmin has since discontinued MapSource and moved users to BaseCamp.

Where it is used

These files turn up in personal archives, in club route collections and on download sites that have been running since the 2000s. Garmin's own newer software and conversion tools such as GPSBabel can still read them, which is usually the only way to get the data out today.

Structure

Both are binary container formats holding a whole workspace rather than a single object: waypoints, routes and tracks together, with Garmin-specific attributes such as waypoint symbols, route calculation settings and map-product references that no text format has anywhere to put. GDB carries a version marker, and readers must know which generation they are looking at.

How widespread

This is a legacy format with a long tail. Nothing new writes it, but a great deal of carefully collected route data was saved in it and still needs converting — which is the whole reason to support it.

RouteConverter support

Reads Garmin MapSource 5.x, Garmin MapSource 6.x
Writes Garmin MapSource 5.x, Garmin MapSource 6.x

RouteConverter handles both generations through the bundled GPSBabel rather than with its own parser, so gpsbabel must be present — the installer ships it.

Specifications and documentation