What is the GDB file format?
The .gdb file is the native database format used by Garmin MapSource and its successor Garmin BaseCamp to store GPS data on a computer. It holds collections of waypoints, routes, and tracks recorded by or prepared for Garmin GPS devices.
The format is binary and proprietary to Garmin Ltd. Files are identifiable by the ASCII signature MsRcd near the beginning - a header marker that distinguishes them from unrelated uses of the .gdb extension (such as InterBase database files or Esri geodatabases). A .gdb file cannot be opened in a plain text viewer; dedicated GPS software is required.
Data is organized in three record types:
- Waypoints - individual coordinate points with a name, symbol, and optional notes.
- Routes - ordered sequences of waypoints defining a planned navigation path.
- Tracks - breadcrumb logs of an actual journey, stored as timestamped coordinate series.
Because .gdb is not an open standard, third-party tools depend on reverse-engineered specifications. GPSBabel, the most widely used GPS data conversion utility, reads and writes .gdb on Windows, macOS, and Linux and can convert it to the open GPX standard or to KML for use in Google Earth. Garmin BaseCamp - the official replacement for the discontinued MapSource - opens .gdb files on Windows and macOS.
For long-term storage or cross-platform sharing, exporting to .gpx is recommended, as GPX is a universal open XML format supported by virtually all GPS software and hardware.
Security & safety
RISK: LOWA Garmin GPS .gdb is a data file, not an executable, so opening one is safe. Main caution: avoid sketchy "GDB viewer/opener" download sites (common PUP/adware bait for obscure extensions) - use the official tools (BaseCamp, GPSBabel). Note that GPS tracks can reveal your home location and routines, so be careful before sharing raw track files publicly.
Format details
in a nutshell- InterBase / early Firebird database - Single-file relational server database from Borland InterBase (and early Firebird); read by connecting a database engine, not a viewer (newer versions use .ib/.fdb).
- Esri File Geodatabase - Not a single file but a FOLDER ending in .gdb containing many internal feature-class files, opened in ArcGIS or the free QGIS.
Programs that open GDB files
Windows2 apps
GPSBabel
Open-source Convert to GPX/KML - choose 'Garmin Mapsource - gdb' as the input format. The reliable free tool. 
Garmin BaseCamp
Free File -> Import to load waypoints/routes/tracks (the modern free replacement for MapSource). 
macOS2 apps
Linux1 app
Technical details
deep spec| Developer | Garmin Ltd. |
| Format type | Binary proprietary GPS database |
| File signature (magic bytes) | ASCII string `MsRcd` near the start of the file |
| MIME type | `application/octet-stream` |
| Coordinate system | WGS 84 (standard GPS datum used by Garmin devices) |
| Data objects stored | Waypoints, routes, and track logs |
| Encoding | Uncompressed binary records; not human-readable |
| Official software | Garmin MapSource (discontinued) and Garmin BaseCamp |
| Third-party conversion | GPSBabel (open-source, Windows / macOS / Linux) |
| Equivalent open format | GPX - recommended for interoperability and archiving |
| Related Garmin format | `.gpi` for Points of Interest, `.trk` for standalone track export |
| Internal versioning | Format version number embedded in file header; differs between MapSource releases |
| Waypoint symbol set | Uses Garmin-specific numeric symbol IDs to reference device map icons |
| Platform support (official) | Windows and macOS; Linux access via GPSBabel only |
| Released | Garmin MapSource GDB, ~2000s |
| Specification | www.gpsbabel.org |
GDB conversions
Community Q&A
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