OSM map: get GeoJSON instead of converting TopoJSON → GeoJSON
Looking to turn a map from TopoJSON into GeoJSON? If your data comes from OpenStreetMap, you do not need an intermediate TopoJSON file: osm2cdr builds the map straight from the OSM source and hands you a ready GeoJSON. That is faster and more accurate than the chain "download TopoJSON → upload to a converter → get GeoJSON": you pick an area on the map, choose the GeoJSON format and download the result with up-to-date OSM data and layers for buildings, roads, water and features.
How TopoJSON differs from GeoJSON
| Format | Extension | Type | Purpose |
|---|---|---|---|
| TopoJSON | .topojson | GIS | Choropleth maps, D3.js visualization, administrative boundaries, compact maps |
| GeoJSON | .geojson | GIS | Web mapping, geodata exchange via API, Leaflet/Mapbox visualization, analytics |
How to get GeoJSON on osm2cdr
- 1Select an area on the map on the osm2cdr home page
- 2Choose the GeoJSON format and, if needed, a style and CRS
- 3Click Export and download the ready GeoJSON file
GeoJSON format properties
| Extension | .geojson |
| Type | GIS |
| Purpose | Web mapping, geodata exchange via API, Leaflet/Mapbox visualization, analytics |
When you need GeoJSON
The GeoJSON format is handy when you need to open the result in a dedicated program and keep working with the map: editing, printing, analysing or embedding it in a project. osm2cdr delivers GeoJSON split into layers with up-to-date OpenStreetMap data, so the file is ready to use right after download.
What changes when going TopoJSON → GeoJSON
Going TopoJSON → GeoJSON preserves both geometry and attributes; only the container model changes — a single file versus a set, the supported field types and the format limits. Such a switch is usually made for compatibility with a specific tool. osm2cdr delivers GeoJSON straight from OpenStreetMap data, with no intermediate TopoJSON file.
If you have your own TopoJSON file (not from OSM)
osm2cdr does not accept or convert third-party TopoJSON files: the service works only with OpenStreetMap data. If you already have your own TopoJSON file that is not from OSM, convert it to GeoJSON with third-party tools: GDAL/ogr2ogr from the command line or QGIS — open the TopoJSON and save the layer as GeoJSON. It is free and runs locally, with no cloud upload.
FAQ: TopoJSON → GeoJSON
Can I upload my TopoJSON file?
Not yet: we don't support uploading TopoJSON files at the moment, so convert your file to GeoJSON with ogr2ogr or QGIS. And if your data comes from OpenStreetMap, you don't need a file at all — osm2cdr exports the map straight into GeoJSON.
Is it free?
Yes, exporting an OpenStreetMap map to GeoJSON on osm2cdr is free. Select an area, the GeoJSON format and download the result.
Which programs open GeoJSON?
The GeoJSON format opens in dedicated programs for its category. See the GeoJSON format page for the full list and details.
Why is this better than an online TopoJSON → GeoJSON converter?
An online converter caps the result quality at the quality of the source TopoJSON file. osm2cdr takes data from the OpenStreetMap source and builds GeoJSON with correct layers directly — with no loss on an intermediate TopoJSON file.