Convert GML to FlatGeobuf Online — Free & Instant
Converting verbose GML XML files to FlatGeobuf produces a compact, binary format that loads dramatically faster in QGIS and cloud-native applications. This is the recommended conversion when you regularly work with large WFS or INSPIRE GML downloads and need fast local access.
File converter
When to convert GML to FlatGeobuf
- Converting large WFS GML downloads to FlatGeobuf for fast QGIS access
- Archiving INSPIRE GML datasets as FlatGeobuf for cloud-native workflows
How to convert GML to FlatGeobuf
- 1
Upload your GML
Drop your .gml file on the upload zone.
- 2
Select FlatGeobuf
Click FlatGeobuf in the format panel.
- 3
Download and use
Open in QGIS or serve from cloud storage via HTTP range requests.
About GML
Geography Markup Language (GML) is an XML-based OGC standard for encoding geographic features. It is the mandatory format for the EU INSPIRE directive and is commonly used in Web Feature Services (WFS) to deliver geospatial data over the web. GML files are highly interoperable across GIS platforms and are natively supported by GDAL, QGIS, ArcGIS, and GeoServer. GML can represent complex geometries, coordinate reference systems, and rich attribute schemas, making it the format of choice for authoritative government and infrastructure datasets.
Strengths
- +OGC standard — maximum interoperability
- +Mandatory for EU INSPIRE datasets
- +Supports complex geometries and CRS metadata
- +Native support in QGIS, ArcGIS, and GeoServer
About FlatGeobuf
FlatGeobuf is a modern, high-performance binary format for geospatial vector data, designed for efficient streaming and cloud-native workflows. Based on FlatBuffers, it supports random access via HTTP range requests, making it ideal for serving large datasets directly from object storage like S3 without a tile server. FlatGeobuf is an OGC Community Standard and is supported by GDAL 3.1+, QGIS, Mapbox, and the GeoJSON ecosystem. Its compact binary encoding is significantly faster to parse than GeoJSON for large datasets.
Strengths
- +Extremely fast read/write — binary encoding
- +Supports HTTP range requests for cloud-native access
- +OGC Community Standard
- +Compact — much smaller than equivalent GeoJSON
Frequently asked questions
Q.How much smaller is FlatGeobuf than GML?
Significantly smaller — GML is verbose XML while FlatGeobuf is a compact binary format. Large GML files can be 10x smaller as FlatGeobuf.