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FlatGeobuf to GML

FlatGeobuf to GML Converter Online | GeoDataViewer

Quick answer: Convert FlatGeobuf to GML online for free. Open your FlatGeobuf data, inspect the map preview, and download GML output locally in your browser — no upload required. FlatGeobuf is a compact binary vector format built for efficient reading, streaming, and distribution of large static geospatial datasets.

Before converting FlatGeobuf to GML

Prepare the input

Choose a complete FlatGeobuf dataset (.fgb). Keep required sidecar files together and check the source coordinate reference system.

Know what you download

GML output is downloaded as a file, or ZIP when the driver generates sidecars. Compare the result against the source before sharing.

Limits and troubleshooting
  • Converting FlatGeobuf to GML can change field types, metadata and presentation. A successful download does not prove every source element survived.
  • Browser memory varies by device. There is no guaranteed unlimited file size; split large datasets or use a desktop GIS when memory or WASM initialization fails.

If something goes wrong

  • Empty or partial preview: confirm the source contains supported vector geometry and compare the source layers with the preview.
  • Wrong continent or distorted geometry: inspect the source CRS, axis order and a known location. Valid syntax alone does not guarantee valid placement.
  • Conversion cannot start: reload while online so processing libraries and WebAssembly can load, then retry a smaller known-good sample. File contents are still processed locally.
  • Incomplete export: compare source/output counts, geometry families and key fields. Inspect warnings and keep the original file.
Source Format Guide

What is FlatGeobuf?

FlatGeobuf is a compact binary vector format built for efficient reading, streaming, and distribution of large static geospatial datasets.

FlatGeobuf focuses on performance. It uses a binary layout that is lighter to parse than text-heavy formats and is well suited to delivering large feature collections without the overhead of a database server.

The format is especially attractive for publish-once, read-many workflows where the main goal is quick transfer and efficient client-side access rather than rich transactional editing.

Common Workflows

Common use cases

  • Download products for large basemap or thematic reference layers.
  • High-volume data publishing where users need a file instead of an API.
  • Intermediate exchange artifacts in automated pipelines that value speed and compactness.
Ecosystem

Where you will encounter it

  • High-performance file downloads.
  • Modern open-source GIS and geospatial ETL tooling.
  • Static dataset distribution where speed matters.
Strengths

Why teams choose FlatGeobuf

  • Binary encoding is more compact and faster to parse than many text formats.
  • Single-file delivery is easy to move and archive.
  • Good fit for large static datasets that do not need a full database container.
Limitations

Where FlatGeobuf gets awkward

  • It is less familiar to many business users than GeoJSON, CSV, or shapefile.
  • Text inspection is not as convenient because the format is binary.
  • Some downstream tools still require legacy or standards-driven export formats.
Conversion steps

How to convert FlatGeobuf to GML online

  1. 1. Add your FlatGeobuf file

    Drop the source data into the converter above. Keep any required sidecar files together when your dataset uses them.

  2. 2. Check the map preview

    Inspect the geometry and attributes before exporting so you can spot missing layers or coordinate-system issues.

  3. 3. Download GML

    Run the conversion and save the generated GML output directly from your browser. Your source file stays on your device.

File Structure

Common file extensions and sidecar files

.fgb
Main FlatGeobuf binary file containing the features and associated spatial index information.
embedded spatial index
FlatGeobuf can carry indexing information inside the file instead of relying on separate sidecars.
Conversion Rationale

Why convert FlatGeobuf to GML?

Teams commonly convert FlatGeobuf into GML when they need an XML-based standards workflow that fits formal data exchange requirements.

  • Teams convert FlatGeobuf when the destination user needs a more familiar format such as GeoJSON, shapefile, or GeoPackage.
  • It is also converted when the next step is tiled publication, database ingestion, or standards-driven XML delivery.
  • GML is commonly used where schema-driven exchange and standards compliance matter more than file size.
  • It is a frequent target in enterprise, government, and specification-heavy environments.
FAQ

Frequently asked questions about FlatGeobuf to GML

What do I need before converting FlatGeobuf to GML?

Choose a complete FlatGeobuf dataset (.fgb). Keep required sidecar files together and check the source coordinate reference system.

What exactly is in the GML download?

GML output is downloaded as a file, or ZIP when the driver generates sidecars. Compare the result against the source before sharing.

How large a FlatGeobuf file can I convert?

The practical limit depends on browser memory, geometry complexity and the conversion driver. Start with a small sample. There is no guaranteed unlimited size and no cloud fallback or payment tier for large files.

Are my FlatGeobuf files sent to a server?

File parsing and conversion run on your device. The page, WebAssembly and map basemaps can make network requests; choosing a file does not upload its contents. Load the required libraries before attempting offline work.

Related Converters

More FlatGeobuf conversion paths

FlatGeobuf to GeoJSON
Open, preview, and convert FlatGeobuf data locally in your browser.
FlatGeobuf to GeoPackage
Open, preview, and convert FlatGeobuf data locally in your browser.
FlatGeobuf to ESRI Shapefile
Open, preview, and convert FlatGeobuf data locally in your browser.

Format workflow cluster

More FlatGeobuf and GML workflows

Use the related viewer, tools, guides, and conversion paths to continue the same GIS task without losing the source format context.