Activities of Local OSM Chapter in Slovakia

The following post was written by Freemap Slovakia, one of the OSM Foundation Local Chapters.

OpenStreetMap is represented in Slovakia by Freemap Slovakia (NGO Freemap) which was founded in 2009 and became recognized as Local OSM Chapter in 2021.

We have 13 regular and 4 registered members. Apart from the organized members, there are several hundred active mappers in Slovakia.

Over the time, we contributed to OSM in many ways and we continue to do so.


General OSM discussion forum related to Slovakia

We maintain osm_sk google group, available to everyone, where all OSM contributors  that deal with Slovakia in OSM are welcome to ask questions and discuss ideas.

Mapping Parties

Once, or twice a year we organize mapping parties, one of which serves as a meeting for our NGO. The parties are always held at different places in Slovakia.

Outdoor photograph of Freemap SK members, holding large "" and "OpenStreetMap" banners.


Our community page can be found here.

Data Imports

Buildings and Addresses

In an effort that has been going for several years we continuously perform supervised bulk import of buildings and addresses from the Cadastre of Real Estate of Slovakia. For this purpose we built a JOSM plugin that allows users to visually inspect batch-imported data and upload it subsequently into the OSM database.

Marked Hiking Trails

Slovakia is a mountainous country and has one of the most elaborate systems of marked hiking trails in the world with more than 100 years of history (shared with Czech Republic).

We cooperate with the Klub Slovenských Turistov (Association of Slovak Tourists) which maintains the physical trails and markings, to make sure all changes are captured in OSM as soon as possible.

Photograph of a guidepost.

Cycling Infrastructure

Slovakia enjoys steady growth of cycling infrastructure, both in physical means (e.g. dedicated cycling paths) and in terms of trail marking. We make sure the latest changes in the “physical world of Slovak cycling” are captured in the OSM database.

Photograph of a guidepost.

Rivers and streams

Rivers and streams are hard to be properly mapped by “survey”, therefore we imported most of the waterways from the Cadastre of Slovakia, open data sources of Slovak Cartography Office of Slovak Republic, INSPIRE dataset and recently from more precise Aerial Laser Scans of Terrain performed by the Geodesy, Cartography and Cadastre Authority of the Slovak Republic.

Software & Hardware Web Portal

We develop and maintain web portal that provides a number of features:

Source code of the portal, backend servers and many utility repositories are Open source.

Screenshot of the website.

Custom Map Styles and Renderers

Due to the specific appearance of the hiking trail marking in Slovakia, we developed several custom map styles which we also render and provide publicly as tiles.

Legacy Hiking Style

This raster map style was used for many years until we developed a more recent, hi-res “outdoor style”. Some people still consider this legacy style a pinnacle in terms of balance between colours, information and general aesthetics, and therefore the style is still available in the portal.

Recent Outdoor Style

A new hi-res raster map style has been in development since 2019, with a more “busy” appearance, as it displays hiking, cycling, cross-country skiing and horse riding marked trails all at once.

On more detailed zoom levels, we blend terrain profile into the map using data from the Aerial Laser Scans of Terrain.

The source code of the map style and renderer is freely available.

Photo Gallery

We empower users of to upload and view photos. Our photo gallery contains almost 300 000 photos, including more than 10 000 photos of hiking and cycling guideposts.

Rendering Maps and Hosting Tiles

We render our own map styles and expose the map tiles for public use. This way, anyone can easily use our raster map tiles in their websites, or smartphone apps.

We also provide offline vector maps for the Android smartphone app Locus and other devices:

Garmin Exports

Twice a week we export the freemap-style map into a format suitable for Garmin devices.


Printed maps

We create custom vector maps for large prints on information boards. users can also easily export their own raster maps in print quality through the Export Map feature.

Photo of an information board, which shows a map, photos and text.

OSM License Compliance

Maps generated from the OSM data are frequently used by various NGOs in Slovakia on information boards and printed maps. When we encounter OSM-based maps missing appropriate attribution, we communicate with creators of those maps to make sure the text is included. In almost all cases such the situation is caused by lack of knowledge and not by malicious intent and the problem is usually resolved by adding a sticker to the board containing the attribution text.


The Openstreetmap Foundation Greatness in mapping award was granted to our member Martin Ždila in 2016.


Our largest expenses are for hosting the portal and the map rendering servers. These costs are covered with income from annual fees paid by our members, by donations, and via the Slovak government-run 2% income tax donation schema.

Vision for Upcoming Years

In the near future we will be busy with the following:

  • we believe that as a community, we succeeded in creating the best outdoor map of Central Europe, with an unmatched level of detail, precision, and frequency of updates. We plan to continue in this effort
  • grow the OSM community in Slovakia and make the existing tools more accessible for non-English speaking mappers.
  • as mostly technology-centric group of people, we realize the need for recruiting new members, who could help us put a more human face on our effort through social media, or by organizing mapping-propagating events for lay people 
  • continue importing data into the OSM database from datasets published by various Slovak government agencies. This also includes cleanup of data that was previously imported from less precise datasets.
  • work on further development of the web portal, the outdoor map style and a custom routing service, most likely based on GrapHopper
  • try to raise more funds, which would allow us to grow the area covered by our map even further

More Resources and Links

  • WikiProjekt Slovensko on (in Slovak)
  • – partner portal build on top of OSM data and maps
  • – partner portal for cross-contry skiing using maps

If you would like to contact us

Write us via osm_sk google group, or through Facebook page, or send us an email to

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The OpenStreetMap Foundation is a not-for-profit organisation, formed to support the OpenStreetMap Project. It is dedicated to encouraging the growth, development and distribution of free geospatial data for anyone to use and share. The OpenStreetMap Foundation owns and maintains the infrastructure of the OpenStreetMap project, is financially supported by membership fees and donations, and organises the annual, international State of the Map conference. It has no full-time employees and it is supporting the OpenStreetMap project through the work of our volunteer Working Groups.

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