Processed locally — your file never leaves your device
TopoJSON to GeoJSON Converter
Convert a TopoJSON topology to standard GeoJSON in your browser — nothing is uploaded.
Drop a GeoJSON, TopoJSON, KML, KMZ, GPX, zipped Shapefile or CSV file hereor click to choose a file from your deviceNothing is uploaded — the file is detected and processed entirely on your device.
How it works
- Select or drop a .topojson (or .json) file containing a topology.
- Your browser decodes its arcs and expands every named object into features, locally.
- Download the resulting .geojson file, or switch to the View tab to see it on a map first.
Frequently asked questions
- What's the difference between TopoJSON and GeoJSON?
- TopoJSON stores shared borders once as 'arcs' instead of repeating them in every neighbouring shape, which makes files considerably smaller. GeoJSON repeats the coordinates, so it's larger but understood by far more tools.
- Is my file uploaded anywhere?
- No. The conversion runs entirely in your browser.
- What if the topology contains several objects?
- Each named object is expanded and merged into one GeoJSON FeatureCollection, with the object's name kept as a 'layer' property so you can still tell the features apart.
- Can I convert GeoJSON back to TopoJSON?
- Not currently. Building a topology means detecting which borders are shared between shapes — a genuinely different and much heavier computation than reading one, so it isn't offered here.