Update or add new Maps to your Sat Nav / GPS for free

This is the simplest tutorial on how to add or update maps to your Garmin Sat Nav.

Garmin maps are simple .img files (files with .img extension). So updating or adding maps is as simple as copying and pasting a file, which has to be named gmapprom.img or gmapsupp.img. In some places, you may find locked files, but there are tools to unlock those.

An additional option (but not free) is to purchase official maps from Garmin’s website. The cost in the UK (Europe map) is £49.99 for a single update or £74.99 for a LifeTime update (updates forever). If your GPS has LMT in the description is because LifeTime updates are included already (no extra charge). Once you get this, you install Garmin software from their website and you get the updates whenever you want.

But because we like free stuff, these are the steps:

Step 1. Buy a cable and connect your Sat Nav

The first step is to connect the device to your computer. For this purpose, you need a mini USB cable. If you are an Andriod user you probably have one already, otherwise, you can get one on Amazon for around USD 3 (option 1, option 2, option 3).

Step 2. Find your Map

Open Street Map (OSM) is the most used and globally recognised map source. They are free, created and updated by users and volunteers across the World.

The easiest thing to do is to find the map of your interest ready to use in .img format. So select your map from this link (once you find the one you need, click on the Provider column), only make sure that it says Yes in the Routable column. In my case I wanted France so I downloaded the map from the following website. There you click on Europe Maps and then Benelux & France.

That’s it! Your browser will start downloading a .zip (if it is compressed) or a .img file. In my case the file is called “Benelux & France-IMG-UL.zip“, and it is around 600MB.

Clarification: If you cannot find your map in the link above, follow the following steps:

1. Go to http://garmin.openstreetmap.nl/
2. In “Choose a predefined country” select Thailand
3. Click “Download map now”
4. Select only the file “osm_generic_gmapsupp.zip” to download.
5. Unzip the file above
6. Copy the unzipped file (gmapsupp.img) to your SD card

[Only for advanced users]: browse the OSM website or other providers to find more specific maps. If your map has .osm extension, use one of these tools to convert it to .img. Mkgmap is a good one.

Step 3. Copy your Map to your Sat Nav

Here you have two options, you can copy the file to your Sat Nav memory, or you can use an external SD card:

Option A: Use your Sat Nav inbuilt memory

You can now just copy and paste your file to your device. Once connected to your computer, it will appear as an additional drive, as shown in the image below.

Copying file to Sat Nav
Copying file to Sat Nav

You may not have enough space on your device, but you can remove some files and replace the existing map. You can always make a backup and copy the files to your computer.

gmapprom.img is the pre-installed map, so you can just replace it. gmapbmap.img is the base map containing only large roads and larger cities, not really suitable for routing. You could delete it but as it is only about 50 MB you wouldn’t gain much space. You can also delete some of the voice files to make room. These probably contain lots of different voices and languages (files with .sum and .vpm extensions) that you never use, so they may take up quite a bit of space. They should all be in the Garmin\Voice directory. This is also only around 50MB. Another option would be to go to garmin.openstreetmap.nl and select only the files you are interested in and see if the generated map fits on your device.

Option B: Use an external SD card

If you do not want to remove nor touch the original maps (the ones that came when you bought your device), you can play safe and use an external SD card (read more at our “Best Travel Gadgets” post). You only need to create a folder called Garmin and copy your .img file in this directory.

You can get a 4GB SD card for around USD 4: Kingston, SanDisk. You need to format it with FAT32 [Windows, Mac]. Garmin says it will only accept up to a 4GB card for certain models, so check that in advance. Newer models can accept cards with more storage, in that case, you can get an Amazon Basics one with 128 GB for $17.

Step 4. Check your new Map in your Sat Nav

To check if the map was copied correctly and is ready to use, follow these steps:

  • Disconnect your Sat Nav from the computer
  • Turn it on and click on Tools (bottom right corner)
  • Click on Settings, then on Map, and then on Map Info.

You should now see your new map, as the image below:

Garmin Sat Nav
Garmin Sat Nav’s Map Info Screen

Recommended devices

You can find many Garmin Sat Navs on Amazon at different prices (from USD 100):

New devices can load multiple “*.img” files. If you want to have more maps on your device you can rename the maps file in
gmapprom.img (original map/ or renamed new map), gmapsupp.img (2° map), gmapprom1.img (3° map), etc.

Some other recommended Garmin Sat Navs are the ones below. Bear in mind that nowadays most of them come with LifeTime maps from the country you buy them from, so better to buy them with the maps you are most likely to need.

Additional tips and information

  • Do not forget to visit our “Best Travel Gadgets” post to find other useful artefacts for your trip!
  • I strongly recommend Skyscanner for searching for both cars and flights. I always find the best deals. For cars, local agencies are normally much cheaper than the big names such as Europcar and Hertz.
  • Are you still having problems with your maps? Please ask for help here.

Support us

A small donation would help us to keep travelling and providing the best advice we can. Simply use this link from Buy Me A Coffee for that.

15 thoughts on “Update or add new Maps to your Sat Nav / GPS for free”

  1. I have read your post on downloading and installing maps from Openstreetmaps.
    Thank you very much for all the info.

    I have attempted to download a street map for Thailand. Have doe the generic for GPS and once downloaded it asks to be burnt onto a CD. This is the only option.
    I also then downloaded the version for windows and this one actually opens. I have then followed your instructions and have copied all files to my SD card as well as memory of my GPS but the map does not want to show. If you like i can send you the file with all the .img files. They are all numbers .ing files. There is no specific file stating that it is Thailand map or so.

    If you could help me with this one I will be greatly appreciate

    1. Hi Harald,
      There is no need to burn anything to a CD nor open the file or any program in Windows or any other operating system. You should:

      1. Go to http://garmin.openstreetmap.nl/
      2. In “Choose a predefined country” select Thailand
      3. Click “Download map now”
      4. Select only the file “osm_generic_gmapsupp.zip” to download.
      5. Unzip the file above
      6. Copy the unzipped file (gmapsupp.img) to your SD card


      1. Can I ask for help? I’ve got a garmin deal 560lt, it doesn’t have lifetime maps. I was getting a message saying it couldn’t unlock maps so I started messing about with the files and downloaded a map from openstreetmaps… but it isn’t showing streets? What have I done wrong? Should I replace the original map with the one I downloaded

  2. I would like to thank you first for sharing this useful info.
    Here I need one more help: I am facing problem with downloading the map.
    Is there any easy or simple way to do this?

    1. The easiest way is to follow the 6 steps in the reply to the previous comment above. What problem are you facing exactly?

  3. Hi..have downloaded files..transferred to sat nav via laptop..but no maps showing on sat nav? Thanks,Rob

  4. This is a great tutorial for downloading free maps for Garmin devices.

    I have one question :

    I’ve got a Nuvi1300, which was purchased originally in North America, and thus has the North American maps by default on the SatNav. I moved to Sydney Australia and therefore had to get the maps for Australia and New Zealand on an SD card. Using the steps mentioned in your tutorial, after downloading the maps on my SD card from https://www.openmapchest.org/maps/australia-new-zealand, how do I update the maps? In the wiki page it’s mentioned that the maps are updated bi-weekly. Would I have to download each time I want to update? Please help to clarify.

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