Convert FlatGeobuf to TopoJSON

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

Ready to convert?

Upload your FlatGeobuf file and get TopoJSON output in seconds.

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.

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.

How to Convert FlatGeobuf to TopoJSON

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

Frequently Asked Questions

How do I convert FlatGeobuf to TopoJSON?

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

Is the FlatGeobuf to TopoJSON 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 TopoJSON files?

TopoJSON files can be opened with D3.js, Mapbox, QGIS, GDAL/OGR and more.

Convert FlatGeobuf to TopoJSON Now

No installation required. Works in your browser.

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