TopoJSON → GeoJSON Converter
Convert TopoJSON back to standard GeoJSON format. Useful when you need to use TopoJSON data with tools that only support GeoJSON, or when you need to expand topology-encoded geometries.
What is TopoJSON?
TopoJSON is a topology-aware extension of GeoJSON that encodes shared arcs to reduce file size. While this is great for storage and transmission, many tools and libraries only work with standard GeoJSON.
When to Convert
Convert TopoJSON → GeoJSON when:
- Using tools that don't support TopoJSON (some GIS software, mapping libraries)
- Editing geometries in standard GeoJSON editors
- Simplifying your data pipeline (GeoJSON is more universal)
- Working with tools that expect FeatureCollection format
How to Convert
- Upload your .topojson or .json file (drag-and-drop or browse)
- Preview the converted GeoJSON on the map
- Download the standard GeoJSON file
Conversion Details
What Gets Converted
- ✅ All geometries: Points, LineStrings, Polygons, MultiGeometry
- ✅ Properties: All feature attributes are preserved
- ✅ Multiple layers: All topology objects are converted and merged
- ✅ Shared arcs: Expanded back to full coordinates
File Size Changes
- GeoJSON will be larger: Typically 2-5× larger than TopoJSON
- Shared boundaries are stored redundantly in GeoJSON
- Use GeoJSON Minifier to reduce precision if needed
Common Use Cases
- Legacy tool compatibility: Using TopoJSON data with older software
- Data editing: Modifying geometries in standard GeoJSON editors
- API requirements: Some APIs only accept GeoJSON
- Learning/debugging: GeoJSON is easier to read and understand
Technical Details
- All topology objects merged: Output is a single FeatureCollection
- Arc expansion: Shared arcs are fully expanded with all coordinates
- Standards compliant: Output follows the GeoJSON RFC 7946 specification
- Client-side processing: Your data never leaves your browser
FAQs
Why is my GeoJSON file larger than the TopoJSON? TopoJSON stores shared boundaries once. GeoJSON stores every boundary for every feature, even if they overlap.
Can I convert back to TopoJSON later? Yes! Use the GeoJSON → TopoJSON converter.
What if my TopoJSON has multiple objects? All objects are converted and merged into a single FeatureCollection.
Do I lose any data in the conversion? No—all geometries and properties are preserved. The file will just be larger.
See Also
- Back to All Converters
- GeoJSON → TopoJSON — Convert the other direction
- GeoJSON Minifier — Reduce GeoJSON file size
- TopoJSON Minifier — Optimize TopoJSON files