Garmin Custom Maps KMZ is the official (since 2010) way to load your own raster map onto Garmin Oregon, Colorado, Dakota, GPSMAP, Montana and etrex navigators without building a vector IMG. Inside is an ordinary ZIP with doc.kml, where each JPEG tile is described by a GroundOverlay section tied to four corners. On osm2cdr we render the chosen area via QGIS into a grid of 1024×1024 JPEG tiles and assemble the finished .kmz entirely on the server. To be honest: it is a flat raster layer at a single detail level — no routing or search, but ready in a minute. We honour Garmin's hardware limit: up to 100 overlays per file.
OpenStreetMap data as of 26 October 2026 · 6 days ago
Vigtigste funktioner

Om formatet Garmin Custom Maps KMZ
Custom Maps is Garmin's official mechanism since 2010: the device reads an ordinary KMZ in which a raster image is tied to the ground by a GroundOverlay section. The format is the same as Google Earth's, so one and the same file opens both on a computer and on a navigator.
This path is chosen for its simplicity. Building an IMG vector map is harder and slower, whereas here a rendered picture is enough: a weekend route, a nature reserve map, a race course diagram, a city walk plan.
The area is rendered into 1024x1024 JPEG tiles — that is the ceiling in Garmin's specification — each described by its own GroundOverlay with corner coordinates, and everything is packed into a ZIP together with doc.kml. The hardware limit is respected: no more than 100 overlays per file.
The limitations are the usual ones for a raster underlay: one level of detail, no routing and no address search. The devices themselves also have an overall cap on the number of custom tiles, which depends on the model — if the layer does not appear, reduce the area.
Hvilket program åbner Garmin Custom Maps KMZ-filer
Følgende programmer og applikationer kan åbne, redigere og arbejde med Garmin Custom Maps KMZ (Tiled JPEG Overlay)-filer (.kmz), der er eksporteret fra OSM2CDR:
Format specifications
- Proprietary format
- 2D only
- Lossy compression
- No attributes
- Output: 1 file
- A Garmin Custom Maps KMZ (ZIP of doc.kml + JPEG GroundOverlays): 1024x1024 tiles at quality 85, a single detail level, up to 100 overlays per the hardware limit.
Hvem bruger Garmin Custom Maps KMZ-kort
Sådan eksporterer du Garmin Custom Maps KMZ
Sådan åbner du filen efter eksporten
- A Garmin device — connect over USB and copy the .kmz into the Garmin/CustomMaps/ folder in internal memory or on the microSD; the layer is enabled in the map settings.
- Google Earth Pro (free) — open the file with a double click and make sure the map lies flat and in the right place, before the trip.
- Garmin BaseCamp — viewing the map on a computer together with tracks and waypoints.
- Check the file size — if it is over a hundred megabytes, the device will pan the map slowly: reduce the area or the detail level.
- If the layer did not appear — check the path (it must be Garmin/CustomMaps), restart the device and remove any extra custom maps: the model has an overall tile cap.
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Download professionelle Garmin Custom Maps KMZ-kort fra OpenStreetMap. Øjeblikkelig generering, ethvert område.