Convert GML to FlatGeobuf

Convert GML (.gml) to FlatGeobuf (.fgb) online for free. Fast, accurate geospatial format conversion with CRS reprojection.

Ready to convert?

Upload your GML file and get FlatGeobuf output in seconds.

About GML

Geography Markup Language (GML) is an OGC XML-based format for expressing geographic features. It is often used for data exchange between government agencies and in INSPIRE-compliant systems.

Extensions: .gml
Software: QGIS, ArcGIS, GeoServer, Deegree, GDAL/OGR
Limitations: Verbose XML format — large file sizes. Complex schema definitions. Slower to read/write than binary formats.

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 GML to FlatGeobuf

  • Upload your GML file (.gml)
  • 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 GML to FlatGeobuf?

Upload your GML 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 GML 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 GML to FlatGeobuf Now

No installation required. Works in your browser.

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