Does this preserve polygon holes (inner rings)?

No. Only each Polygon's outer boundary ring is written to KML's outerBoundaryIs element, any inner rings (holes) in the source GeoJSON are dropped. This is a stated limitation of a deliberately straightforward converter, not an oversight.

What happens with MultiPoint, MultiLineString, and MultiPolygon geometries?

Each is flattened into multiple separate Placemark elements, one per member geometry, since KML's Placemark doesn't have a native "multi-geometry-in-one-element" concept as simple as GeoJSON's. A MultiPolygon with 3 polygons, for example, becomes 3 Placemarks.

Does the output include styling, colors, or icons?

No, this converter only emits geometry and, where present, a name. KML supports rich styling (icons, line colors, fill colors) but GeoJSON's Feature properties don't map to that in any standard way, so this tool doesn't attempt to invent styling from arbitrary properties.

Can I convert a single Feature instead of a full FeatureCollection?

Yes, pasting a bare Feature object (one with "type": "Feature") is automatically wrapped in a one-element FeatureCollection before conversion, so you don't need to wrap it yourself.

GeoJSON to KML Converter - Convert GeoJSON to KML XML

Overview

Introduction

Most GeoJSON to KML converters try to preserve every possible KML feature, styling included, which adds a lot of surface area for something that's often just needed for a quick geometry export. This one deliberately doesn't.

Paste GeoJSON, get back straightforward KML XML: one Placemark per feature, named where a name property exists, geometry only, no styling.

What Is GeoJSON to KML Converter?

A hand-written GeoJSON-to-KML converter, since no KML-writing library is bundled with this tool. KML is a simple, well-documented XML format, so building it directly from a template is both easy to verify and easy to keep predictable.

It supports GeoJSON's Point, LineString, and Polygon geometries (outer ring only) directly, and flattens Multi* geometries into multiple Placemarks, one per member.

How GeoJSON to KML Converter Works

The pasted text is JSON.parse'd and checked for a FeatureCollection or Feature shape (a bare Feature is wrapped in a one-element FeatureCollection automatically), then each feature's geometry is matched against a small set of supported types.

For each feature, a <Placemark> element is built with an optional <name> from properties.name, followed by exactly one geometry element (Point, LineString, or Polygon with outerBoundaryIs only), all text content is XML-escaped before being embedded.

When To Use GeoJSON to KML Converter

Use this when you have GeoJSON geometry and need a quick, valid KML file for Google Earth or another KML-reading tool, without needing anything more than geometry and names to carry over.

It's not the right tool if you need polygon holes, per-feature styling, or icons preserved, those need a more elaborate KML writer.

Often used alongside KML to GeoJSON Converter and GeoJSON Viewer.

Features

Advantages

Runs entirely client-side, your GeoJSON data never leaves your browser.
Simple, predictable output: one Placemark per feature, easy to review and diff.
Handles Multi* geometries by flattening them into multiple Placemarks rather than silently dropping them.

Limitations

Polygon inner rings (holes) are not written to the output, only the outer boundary.
No styling, icons, colors, or line widths are emitted, geometry and name only.
GeometryCollection and any other unrecognized geometry type is skipped rather than converted.

Examples

A named Point feature

Input

{"type":"Feature","properties":{"name":"Home"},"geometry":{"type":"Point","coordinates":[-122.4,37.8]}}

Output

<Placemark><name>Home</name><Point><coordinates>-122.4,37.8</coordinates></Point></Placemark>

The feature's properties.name becomes the Placemark's <name>, and the Point geometry's coordinates carry over directly in lon,lat order.

Best Practices & Notes

Best Practices

Add a name property to features you care about identifying, it's the only property this converter carries through to the output.
If your polygons have holes, expect them to be simplified to just the outer boundary, and mention that when sharing the KML downstream.
Check the reported feature/Placemark count against your source, a MultiPolygon or MultiLineString will produce more Placemarks than input features, which is expected.

Developer Notes

`convertGeoJsonToKml` in `geojson-to-kml-converter.ts` builds KML as a plain template string, `escapeXml` handles the three characters that matter for well-formed embedded text (&, <, >), and `geometryToPlacemarks` returns a `string[]` per feature (usually length 1, longer for Multi* geometries) so the caller can simply `.flatMap()` across all features to get the final Placemark list, no XML-building library involved.

GeoJSON to KML Converter Use Cases

Exporting GeoJSON geometry from a web map or API into a KML file for Google Earth
Converting a GeoJSON dataset's points/lines/polygons into KML for a client that only accepts KML
Quickly checking what a GeoJSON FeatureCollection looks like translated into KML's Placemark structure

Common Mistakes

Expecting polygon holes to survive conversion, only outer rings are written, this is a stated limitation, not a bug.
Assuming styling (colors, icons) carries over from GeoJSON, there's no standard GeoJSON-to-KML styling mapping, so none is invented here.

Tips

If you need styling in the final KML, add it by hand in a KML editor after conversion, this tool focuses on getting the geometry right first.
Use GeoJSON Viewer beforehand to sanity-check the source geometry, so you know what to expect in the converted KML.

GeoJSON to KML Converter