Convert TopoJSON to FlatGeobuf

Convert TopoJSON (.topojson, .json) to FlatGeobuf (.fgb) online for free. Fast, accurate geospatial format conversion with CRS reprojection.

Ready to convert?

Upload your TopoJSON file and get FlatGeobuf output in seconds.

About TopoJSON

TopoJSON is an extension of GeoJSON that encodes topology, eliminating redundancy and reducing file size. Shared boundaries between features are stored only once.

Extensions: .topojson, .json
Software: D3.js, Mapbox, QGIS, GDAL/OGR, Leaflet
Limitations: Read-only in most GIS software. Requires conversion for editing. Less widely supported than GeoJSON.

About FlatGeobuf

FlatGeobuf is a performant binary encoding for geographic data based on FlatBuffers. It supports streaming and random access for fast partial reads.

Extensions: .fgb
Software: QGIS, GDAL/OGR, Leaflet, OpenLayers, GeoServer
Limitations: Relatively new format with limited support in older software. Single layer per file.

How to Convert TopoJSON to FlatGeobuf

  • Upload your TopoJSON file (.topojson, .json)
  • Review detected layers, features, and coordinate system
  • Select FlatGeobuf as your output format
  • Choose a target coordinate reference system (optional)
  • Click Convert and download your FlatGeobuf file

Frequently Asked Questions

How do I convert TopoJSON to FlatGeobuf?

Upload your TopoJSON file to ConvertGeoData, review the detected data, select FlatGeobuf as the output format, and click Convert. Your converted file will be ready to download in seconds.

Is the TopoJSON to FlatGeobuf conversion free?

Yes! ConvertGeoData offers free conversions for all users. No account required for basic conversions. Sign up for a Pro or Business plan for higher limits.

Can I change the coordinate system during conversion?

Yes. ConvertGeoData automatically detects your source CRS and lets you reproject to any EPSG coordinate reference system during conversion.

What software can open FlatGeobuf files?

FlatGeobuf files can be opened with QGIS, GDAL/OGR, Leaflet, OpenLayers and more.

Convert TopoJSON to FlatGeobuf Now

No installation required. Works in your browser.

Stop emailing zip files and hoping for the best.

GeoShare: cloud preview + flexible download for every geospatial file you share. Coming soon to ConvertGeoData.