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The development and support of this program has been discontinued!
It is still available for download, see below.

JaVaWa MapConverter

JaVaWa MapConverter converts Garmin maps in the old format (those who use configuration settings in the Windows Registry) to the new .gmap format.

Garmin's MapConverter is able to convert maps only when they have references in the Windows Registry. JaVaWa MapConverter goes beyond that: it can create a .gmap map out of a collection of several files; not only under Windows, but on the Mac too!
Ofcourse that collection of files has to be a complete set. Later in this document you will find an exact description of the files that need to be in that collection, but before you start to read that (technical) description it's better to try and convert some maps.

How to use JaVaWa MapConverter

Drag the folder (or zip archive) with the files to the window of JaVaWa MapConverter; the program will determine whether the collection is useful and which map it is. In most cases JaVaWa MapConverter will be able to decide what the purpose of each of the files is, but sometimes it isn't clear which .img file contains the overview map. In that case you will need to pick the right one.

When no error messages are shown you can click "Convert" or "Convert & Install". The first option converts the map and places it in a folder of your choice; the second one puts the converted map in the right place, so that it can be used with BaseCamp and MapSource right away.
You can always install (or remove) the converted map later on your computer with JaVaWa GMTK.

Alternatively, when you have a backup of a registry map made with JaVaWa GMTK you can drag the folder containing the file with the extension .gmtkd to the window, or the .gmtkd file itself. In that case the purpose of every file is clear, and no extra questions will be asked.

When you use JaVaWa GMTK to migrate maps from PC to Mac you don't need JaVaWa MapConverter; the required functionality is integrated in JaVaWa GMTK.

When you use the option "Convert & Install" the program will ask for elevated privileges, when needed. This is the case when your user account has no writing privileges for the folder where the map will be installed..
If you want to install the map in another location than the default one, use "Convert" and install the map with JaVaWa GMTK in the folder of your choice.


The files a map consists of

A Garmin map always consists of a collection of several files. In the table below you will find a description of each of them:

TDB.tdbalwaysThis is an index file that is used by MapSource and BaseCamp to decide which map segments have to be loaded in memory for the display. MapConverter uses this information to decide which .img files belong to the map. When one or more is missing, the map cannot be converted.
overview map.imgalwaysEvery map contains a simplified overview map, which is used when you zoom out.
map segment.imgalwaysEvery map contains at least one of them, but usually more. They always have a name consisting of 8 digits (and the extension .img).
MDR.imgsometimesContains a search index. Will be used when you search for e.g. an address, city or POI.
MDX.mdxsometimesThis is a kind of search index too, but this one descibes the relations between the regional maps.
TRF.trfsometimesIt isn't clear what the purpose of this file is; commonly seen in City Navigator maps.
TYP.typsometimesThis file contains the style information used for the display of the map elements.

Note: some maps like the BlueChart maps consist of several parts: the map itself and the tide tables. JaVaWa MapConverter converts only the first part. When you have a map like that, use Garmin MapConverter instead.

Command line version

There is also a command line version of JaVaWa MapConverter available for those who want to use the program in a workflow on this page.


The Windows version of JaVaWa MapConverter uses 7-Zip for decompressing ZIP files.

This software is unsupported!

Download JaVaWa MapConverter for Windows

Download JaVaWa MapConverter for MacOS

JaVaWa MapConverter is a 32-bit program, and therefore not
compatible with MacOS Catalina and above!
Last updated: 2023-11-03
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