Convert KML to GML Online - Free & Fast

What is KML?

KML (Keyhole Markup Language) is Google Earth's native format for geographic annotation, supporting placemarks, polygons, 3D models, and image overlays.

What is GML?

GML (Geography Markup Language) is the OGC standard XML grammar for encoding geographic features with full coordinate reference system support.

When Should You Use KML vs GML?

KML vs GML: Key Differences

• •KML uses lossless compression while GML uses lossless compression — both take the same approach to file size management.
• •Neither format changes compression philosophy — both are lossless compression — so any size differences are due to encoding efficiency, not a shift in quality approach.
• •Transparency: N/A
• •File sizes: KML files typically range 1KB to 50MB for complex overlays and GML files Larger than Shapefile due to verbose XML structure.
• •Primary audience: KML is built for google earth visualization, geographical overlays, placemarks scenarios, while GML focuses on ogc-compliant geospatial data exchange, enterprise gis — pick the format that matches your output requirement.

Advantages of KML

• ✓The lossless nature of KML means file sizes stay reasonable while handling Google Earth visualization, geographical overlays, placemarks efficiently.
• ✓From mobile devices to enterprise servers, KML is recognized and supported everywhere.
• ✓The trade-off for KML's perfection is larger files — but for archival work, it is worth every megabyte.
• ✓KML is a first-class citizen in all major software ecosystems, from creative suites to development environments.

Advantages of GML

• ✓The lossless nature of GML means file sizes stay reasonable while handling OGC-compliant geospatial data exchange, enterprise GIS efficiently.
• ✓From mobile devices to enterprise servers, GML is recognized and supported everywhere.
• ✓The trade-off for GML's perfection is larger files — but for archival work, it is worth every megabyte.
• ✓GML is a first-class citizen in all major software ecosystems, from creative suites to development environments.

Common Use Cases for KML to GML Conversion

Industry Applications

Best Practices for KML to GML Conversion

• →When converting KML to GML: confirm the coordinate reference system (CRS / projection) is preserved or explicitly reprojected
• →Keep attribute tables and feature metadata intact — GML should retain all fields from KML
• →Check geometry types (point, line, polygon) map cleanly between the two formats
• →Verify that z/elevation values and topology survive the conversion when working with terrain data
• →Always keep a backup of your original files before converting
• →Choose the appropriate quality settings for your specific use case

Troubleshooting KML to GML Conversion

• !Topology errors in the converted GML → self-intersecting polygons or duplicate vertices may not transfer cleanly between formats
• !The GML file coordinate values shifted slightly → datums (WGS84 vs NAD83) differ even when the projection looks similar
• !Time field values were corrupted after converting KML to GML → date and time field formatting varies across GIS formats
• !Null geometry features appear in the converted GML → empty or null-shape records in KML may cause validation errors in some formats

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