Convert TopoJSON to GeoJSON online
Convert TopoJSON — the compact, topology-aware JSON format used by D3 and many web maps — into GeoJSON, which is the open, web-native JSON format read by Leaflet, Mapbox and virtually every modern GIS tool. Drop your TopoJSON file below, GeoJSON is already selected as the output, and download the result. Everything runs in your browser and the cloud; you never install anything.
Upload your file
Drag and drop it into the converter below. A free account comes with three welcome conversions.
Convert in the cloud
MapGO detects the format and produces your download in seconds.
Download & keep it
Files are deleted automatically after 48 hours.
Files are deleted automatically after 48 hours. Your files are never shared.
Why convert TopoJSON to GeoJSON with MapGO?
Most online converters take one file and hand back one file. MapGO is built on a real geospatial engine, so a single upload can do more.
- Several outputs in one upload
Tick GeoJSON and any other formats you need; every selected format is delivered from the same file.
- Files up to 5 GB
Far beyond the browser-based converters that choke past a few hundred megabytes.
- Reproject while you convert
Set a source and target EPSG code and the coordinate system is changed during the conversion, no second tool needed.
- Private by default
Files are deleted automatically after 48 hours.
TopoJSON vs GeoJSON at a glance
| TopoJSON | GeoJSON | |
|---|---|---|
| Typical use | D3 visualisations and lightweight web maps | Web maps and APIs (Leaflet, Mapbox, D3); human-readable data in git |
| Size on disk | Very small — shared borders are stored once | Verbose plain text — the largest of the common formats, but gzips well |
| Attribute support | Properties per shape, like GeoJSON | Flexible JSON properties — nesting and arrays allowed |
| Software support | D3, Mapshaper, GDAL-based tools | Every modern GIS tool and every web mapping library |
| Web-friendliness | Excellent in D3; most other tools want GeoJSON | Excellent — the native format of web mapping |
Other ways to convert TopoJSON to GeoJSON
You don't need an online tool for this. If you have GDAL installed, one command does it.
In QGIS (free): open your TopoJSON via Layer → Add Layer, then right-click the layer → Export → Save Features As… and pick GeoJSON as the format.
The MapGO converter above is for when you don't want to install anything, need to convert to several formats at once, or are handling files too large for a desktop machine.
ogr2ogr -f "GeoJSON" output.geojson input.topojsonTopoJSON to GeoJSON: frequently asked questions
Is the TopoJSON to GeoJSON converter free?
Partly. Every new account gets three welcome conversions for free, so you can try TopoJSON to GeoJSON without paying. After that, you can either buy a credit pack and pay per conversion, or take a subscription, which gives you unlimited conversions within the plan's file-size limit. There is nothing to install; the whole conversion runs in the cloud.
Is my data kept private?
Conversion is fully automated and your file is never shared. Files are deleted automatically after 48 hours. Download your GeoJSON result and it's yours to keep.
What does the GeoJSON output contain?
You get a clean GeoJSON file with your geometry and attributes preserved, ready to open in the tools that read GeoJSON.
My TopoJSON has several objects — which one is converted?
Each TopoJSON object becomes a layer, and MapGO converts the one with the most shapes. The others are named in a note on the finished conversion.
Which coordinate system will the GeoJSON output use?
By default the output keeps your source coordinate system; pick EPSG:4326 (WGS84) as the target if you want spec-standard GeoJSON that works immediately in Leaflet, Mapbox and other web libraries. MapGO reprojects during the conversion — no separate step needed.
Also convert
See it on the map first.
Open your TopoJSON in the workspace, check the shapes and attributes, then convert and download from the same place.