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Convert GeoPackage to GML Online — Free GIS Converter

Convert GeoPackage (.gpkg) to GML for OGC WFS publication, EU INSPIRE compliance, and authoritative government data exchange.

Updated May 2026

Convert GeoPackage files into GML — the OGC Geography Markup Language required for WFS services, EU INSPIRE directive compliance, and formal government-to-government spatial data exchange.

Why convert GeoPackage to GML?

GeoPackage is an excellent working format for analysis and offline storage, but publishing spatial data through an OGC Web Feature Service (WFS) or submitting to a regulatory authority often requires GML. The EU INSPIRE directive mandates that member-state spatial datasets be served as GML via WFS 2.0 endpoints. National mapping agencies in many countries similarly require GML submissions for authoritative boundary updates, cadastral data exchange, and environmental reporting.

If your organization stores authoritative datasets in GeoPackage for local use and needs to fulfill a WFS publication or regulatory submission requirement, converting GPKG to GML is the last step in that pipeline — and it needs to be done correctly, including CRS declaration and GML version selection.

Why use geodata.plus

  • Free tier: convert up to 3 files per month at no cost
  • Outputs GML 3.2 (ISO 19136) — required by INSPIRE and OGC WFS 2.0
  • Full CRS preservation and optional reprojection to any EPSG code
  • Handles multi-layer GPKG files — select the target layer
  • Browser-based — no GeoServer, GDAL, or command-line tools required
  • Encrypted upload (TLS); files stored in Cloudflare R2, automatically deleted after 2 days (free) or 7 days (Pro)

How it works

  1. Upload your GeoPackage file to geodata.plus
  2. geodata.plus opens the SQLite database and lists available vector layers
  3. Select the target layer and GML as the output format; choose target CRS if needed
  4. Download your .gml file — ready for WFS publication or regulatory submission

GeoPackage format

GeoPackage is an OGC open standard based on SQLite. It stores vector and raster layers in a single portable file, supports any coordinate reference system, and can be queried directly with SQL. It is the preferred working format in QGIS and ArcGIS Pro for analysis and offline field use.

| Property | Value | |---|---| | Extension | .gpkg | | Type | Vector (and raster), single-file SQLite | | Coordinate system | Any CRS | | Geometry types | Point, LineString, Polygon, Multi* variants, GeometryCollection | | Common software | QGIS, ArcGIS Pro, GDAL, mobile GIS, offline workflows |

GML format

GML (Geography Markup Language) is an OGC XML grammar for geographic feature encoding. GML 3.2 (ISO 19136:2007) is the current version mandated by INSPIRE and most modern WFS services. The format supports arbitrary CRS declarations, rich topology, and extensible application schemas. GML files are verbose but self-describing and fully interoperable across OGC-compliant systems.

| Property | Value | |---|---| | Extension | .gml | | Type | Vector, single-file XML | | Coordinate system | Any CRS (declared in-file using URN or URL notation) | | Geometry types | Point, Curve, Surface, Multi* variants, complex topology | | Common software | ArcGIS, QGIS, GeoServer, MapServer, WFS endpoints, government portals |

Frequently asked questions

My GeoPackage uses EPSG:25832 (ETRS89/UTM zone 32N) — will the GML preserve that CRS? Yes. geodata.plus reads the CRS from the GeoPackage's gpkg_spatial_ref_sys table and writes the corresponding srsName attribute in the GML geometry elements using the OGC URN notation (e.g., urn:ogc:def:crs:EPSG::25832). This is the correct format for INSPIRE-compliant GML and will be recognized by GeoServer, MapServer, and most WFS clients.

Is the GML output compatible with INSPIRE data themes? The GML produced by geodata.plus uses the GML simple feature profile — it does not include domain-specific INSPIRE application schemas (e.g., AdministrativeUnit, Parcel, HydroObject). For basic WFS publication and many government portals, the simple feature profile is acceptable. For strict INSPIRE Annex theme compliance, the output GML must be further mapped to the relevant INSPIRE XSD schema using a tool like HALE Studio or FME before submission.

How large can my GeoPackage be for GML conversion? GML is a verbose XML format — a GeoPackage with 50,000 features may produce a GML file several times larger than the source because each geometry is encoded as human-readable XML text. Conversion works for typical government datasets (thousands to tens of thousands of features), but for very large datasets (hundreds of thousands of features), consider whether your WFS publication pipeline can consume the GeoPackage directly via GeoServer's native GPKG datastore, which avoids the intermediate GML file entirely.

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