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Spatly

Convert GeoJSON to KML

1

Add your GeoJSON

Drop a GeoJSON file anywhere on this page

.geojson · .json · it never leaves the browser

2

Options

≈ 11 cm on the ground
Keep every vertex
00verticesunchanged
Becomes <name>; the rest goes into ExtendedData.
Becomes the balloon text.
3

Your KML

Add a GeoJSON file and the KML appears here, with its feature counts and anything this pair cannot carry.

Converted in this tab. Your GeoJSON is never uploaded — reading, converting and writing all run in the browser, so this works offline once the page has loaded.
— , —
FidelityGeoJSON → KML

What comes across, and what cannot

Preserved

  • Geometry — points, lines and polygons come across coordinate for coordinate; nothing is reprojected, because both sides are WGS84 longitude/latitude.
  • Every attribute survives, with its name intact.
  • Elevation (the Z ordinate) is preserved where the source has one.

Worth knowing

  • Nothing measurable. Both GeoJSON and KML carry geometry and a full attribute table, so this conversion is lossless apart from any coordinate rounding or simplification you ask for.

GeoJSON (RFC 7946)

The web's lingua franca for vector data: plain JSON, WGS84 longitude/latitude, every geometry type, and an untyped property bag per feature. It carries no styling — colour and symbology belong to the map, not the file.

.geojson · .json · application/geo+json

Keyhole Markup Language (KML)

The XML format Google Earth popularised. Placemarks carry a name, a description balloon, a geometry and — unlike GeoJSON — presentation: styles, icons, colours, altitude modes and time stamps.

.kml · application/vnd.google-earth.kml+xml

AlsoKML to GeoJSONShapefile to KMLKMZ to KMLGeoJSON to GPXAll conversions
HowHow it works

Convert GeoJSON to KML, step by step

  1. Step 1

    Add your GeoJSON

    Drop a GeoJSON file anywhere on the page, paste it, point at a URL, or press Sample to start from real data. Several files at once are fine.

  2. Step 2

    Set what matters

    Coordinate precision and simplification on every pair, plus the handful of settings this one needs — which field becomes the placemark name and description.

  3. Step 3

    Take the KML

    Read the feature counts and the warning list, then download, copy, or open the result in the Spatly studio to style and publish it.

PrivateRuns in your browser

Your data never leaves the page

Every conversion, measurement and export happens client-side. Nothing is uploaded, logged or stored — you can even use this offline once the page has loaded. Only “Open in Studio” sends data, and only after you sign in.

Go furtherTurn a GeoJSON into an interactive mapRead the guide
FAQQuestions

Good to know

What is preserved when converting GeoJSON to KML?
Geometry — points, lines and polygons come across coordinate for coordinate; nothing is reprojected, because both sides are WGS84 longitude/latitude. Every attribute survives, with its name intact. Elevation (the Z ordinate) is preserved where the source has one.
What is lost converting GeoJSON to KML?
Nothing measurable. Both GeoJSON and KML carry geometry and a full attribute table, so this conversion is lossless apart from any coordinate rounding or simplification you ask for.
Does the file have to be a FeatureCollection?
No. A bare geometry, a single Feature, an array of geometries or a FeatureCollection are all accepted, and a common API envelope such as { data: … } is unwrapped for you.
Which field becomes the placemark name?
Whichever you choose in step 2. The tool pre-selects a field called name, title or label if it finds one; every other attribute is written into <ExtendedData> so Google Earth shows it in the balloon. You can also nominate a field to become the <description>.
Will the output open in Google Earth?
Yes — the file is KML 2.2 with a single <Document>, one <Placemark> per feature and no vendor extensions, which is what Google Earth, Google My Maps, QGIS and ArcGIS all read.
Is my file uploaded anywhere?
No. The GeoJSON is read, converted and written entirely inside this page — there is no upload, no queue, no server-side copy and no size limit imposed by a plan. Large files are parsed in a background worker so the page stays responsive. The only action that transmits anything is Open in Studio, and that happens after you sign in and press it.
Is there a limit on file size or number of files?
There is no imposed limit; the practical ceiling is your browser's memory. Files over about 5 MB are handed to a web worker so the interface keeps responding, and you can drop several files at once — each is converted separately and the set can be downloaded as one zip.