Free online GDB.ZIP to KMZ converter

What the GDB.ZIP format is

In this context, GDB.ZIP is a ZIP archive containing a Garmin .gdb database. Garmin MapSource and older versions of Garmin BaseCamp use GDB files for waypoints, routes, tracks, and related GPS data; downloaded GPS exports and device backups are common places to encounter them.

The .gdb extension can also refer to an Esri file geodatabase. That format is normally a folder containing multiple files, often distributed as a ZIP archive, and it requires GIS software rather than Garmin conversion software. Check the extracted contents and the program that created the archive before converting.

What the KMZ format is

KMZ is a ZIP-compressed KML package used by Google Earth, Google Earth Pro, and many GIS applications. Its main file is normally doc.kml; the package can also contain custom icons, images, ground overlays, and network-linked resources.

Compared with an uncompressed KML file, KMZ keeps related resources together and is usually smaller. It is suitable for sharing GPS tracks, routes, points, and map overlays, but it is not a full replacement for a Garmin database or a GIS geodatabase.

How to actually convert GDB.ZIP to KMZ

Using GPSBabel for a Garmin GDB file

1. Make a backup of the original archive, then extract GDB.ZIP with your operating system, 7-Zip, or another archive utility.
2. Confirm that the extracted item is a Garmin .gdb file. If it is another ZIP archive, extract that archive as well.
3. Install GPSBabel, select Garmin MapSource Database as the input format, and choose the extracted .gdb file.
4. Select Google Earth KML as the output format and save the result as doc.kml. In the graphical interface, use Input → Format → Garmin MapSource and Output → Format → Google Earth KML, then start the transfer.
5. Package the KML as KMZ. The KML must be named doc.kml and placed at the top level of the archive. With 7-Zip, run 7z a -tzip output.kmz doc.kml. On systems with the standard ZIP utility, run zip -j output.kmz doc.kml.
6. Open output.kmz in Google Earth or a compatible GIS application and verify the points, route lines, and track geometry.

GPSBabel can also perform the data conversion from a command line:

gpsbabel -i gdb -f input.gdb -o kml -F doc.kml

After that command, package doc.kml into a ZIP archive and use the .kmz extension. If the GDB version is unsupported, open it in Garmin BaseCamp or MapSource first and export it as KML, GPX, or another format that GPSBabel can read.

Using the online converter

You can convert the file on the 101convert.com website for free without installing software. Upload the GDB.ZIP file if the converter accepts the archive directly; otherwise extract the Garmin .gdb file first and submit that file. Download the resulting KMZ and test it in the intended application.

If the archive contains an Esri geodatabase

Open the extracted geodatabase in QGIS or ArcGIS instead of GPSBabel. In QGIS, add the relevant layer, use Layer → Export → Save Features As…, choose KML, and then package the exported KML as .kmz with the ZIP command above. A geodatabase can contain multiple feature classes, so export each required layer or combine them before creating the package.

Quality, compatibility, and limitations

The conversion preserves geographic features that the source reader can interpret, but Garmin- or GIS-specific metadata may be discarded. Track timestamps, route instructions, custom Garmin properties, coordinate systems, labels, icons, and styling may require manual checking.

Garmin GDB files can contain several data types at once. Select waypoints, routes, and tracks explicitly if the converter offers those options, and verify that the output uses the expected coordinate system, normally WGS 84 for Google Earth.

A valid KMZ should open as a ZIP archive containing doc.kml at its root. Do not place the KML inside an extra directory, and do not create a file named output.kmz.zip; enable file-extension display in the file manager if necessary. Large tracks may need simplification for faster rendering, but simplifying them reduces positional detail.