Convert GML to GEOJSON

Understanding GML and GeoJSON file formats

GML (Geography Markup Language) is an XML-based format developed by the Open Geospatial Consortium (OGC) for expressing geographical features. It is widely used for sharing complex geospatial data between GIS (Geographic Information System) applications and supports a rich set of geometry types and metadata.

GeoJSON is a lightweight, JSON-based format designed for encoding a variety of geographic data structures. It is popular for web mapping and data exchange due to its simplicity and compatibility with many modern GIS tools and web applications.

Why convert GML to GeoJSON?

Converting GML to GeoJSON is often necessary when you need to use geospatial data in web applications, share data with users who prefer the simpler GeoJSON format, or integrate with platforms that do not support GML natively.

How to convert GML to GeoJSON

The most reliable and widely used tool for converting GML to GeoJSON is GDAL/OGR, an open-source geospatial data translation library. The ogr2ogr command-line utility, part of GDAL, supports both formats and provides robust conversion capabilities.

Step-by-step conversion using GDAL/OGR

1. Install GDAL from the official website or your package manager.
2. Open your terminal or command prompt.
3. Run the following command:
   ogr2ogr -f GeoJSON output.geojson input.gml
4. The resulting output.geojson file will contain your converted data.

Alternative: Using QGIS for conversion

QGIS is a free, open-source GIS application with a user-friendly interface for file conversion:

1. Open QGIS and use Layer → Add Layer → Add Vector Layer to load your GML file.
2. Right-click the layer in the Layers panel and select Export → Save Features As....
3. Choose GeoJSON as the format and specify the output file name.
4. Click OK to complete the conversion.

Best software for GML to GeoJSON conversion

• GDAL/OGR – Best for command-line users and batch processing.
• QGIS – Ideal for users who prefer a graphical interface and additional GIS features.
• Online converters (e.g., MyGeodata Converter) – Useful for quick, small-scale conversions without software installation.

Conclusion

Converting GML to GeoJSON is straightforward with tools like GDAL/OGR and QGIS, ensuring your geospatial data is accessible and compatible with a wide range of applications.