Convert KML to GEOJSON 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 GEOJSON?

GeoJSON is the standard format for web-based geographic data, encoding points, lines, polygons, and feature collections in JavaScript Object Notation.

When Should You Use KML vs GEOJSON?

KML vs GEOJSON: Key Differences

• •KML and GEOJSON diverge on compression: lossless compression for the source, lossless compression for the target.
• •Neither format changes compression philosophy — both are lossless compression — so any size differences are due to encoding efficiency, not a shift in quality approach.
• •How transparency is handled: GEOJSON supports transparency, so alpha information is preserved during conversion.
• •Storage footprint: 1KB to 50MB for complex overlays for KML vs 1KB to 100MB for large datasets for GEOJSON.
• •KML is optimized for google earth visualization, geographical overlays, placemarks while GEOJSON is designed for web mapping, geospatial apis, data interchange — choose based on your specific workflow needs

Advantages of KML

• ✓KML uses lossless compression tailored for Google Earth visualization, geographical overlays, placemarks.
• ✓KML is supported natively on virtually every device, browser, and operating system.
• ✓KML files are bit-for-bit perfect, preserving every pixel and sample for professional work.
• ✓KML integrates seamlessly with all major creative tools and workflows.

Advantages of GEOJSON

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

Common Use Cases for KML to GEOJSON Conversion

Industry Applications

Best Practices for KML to GEOJSON Conversion

• →When converting KML to GEOJSON: confirm the coordinate reference system (CRS / projection) is preserved or explicitly reprojected
• →Keep attribute tables and feature metadata intact — GEOJSON 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 GEOJSON Conversion

• !GEOJSON features land in the wrong place after KML to GEOJSON → verify the CRS/projection; mismatched coordinate systems shift geometry
• !Attribute columns missing in GEOJSON → some GIS formats have field name length or type limits; rename or cast columns first
• !KML to GEOJSON drops the z/elevation dimension → pick a target format that supports 3D geometry
• !GEOJSON file won't open in your GIS app → confirm the format version and any required sidecar files (e.g. .prj, .shx) are present

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