# KML to GeoJSON converter

> Take placemarks from Google Earth or Google My Maps to a web map: get a GeoJSON FeatureCollection for Leaflet, MapLibre or an import. Free, and no account needed.

Open the tool: https://spatibase.com/tools/kml-to-geojson/

The Spatibase KML to GeoJSON converter reads a KML or KMZ file with the open-source togeojson library and writes a GeoJSON FeatureCollection in your web browser. What carries over:

- **Every placemark as a feature.** Points, lines, polygons and Google Earth tracks, with altitude where the KML has it.
- **Its data as properties.** Name, description as plain text, the folder path, ExtendedData fields and the style colours.
- **No upload.** The file is read on your computer, up to 50 MB, free and without an account.

## What it does
- Convert KML and KMZ files to GeoJSON
- Reads Google Earth and Google My Maps exports, folders included
- Keeps ExtendedData and typed SchemaData fields as properties
- Turns KML styles into simplestyle properties such as fill and stroke
- Keeps altitude and the times of a Google Earth track
- Writes standard RFC 7946 GeoJSON in WGS 84
- Runs in the browser: nothing is uploaded

## How to convert KML to GeoJSON
1. Export the KML. Google My Maps: the three-dot menu by the map title → Export to KML/KMZ. Google Earth Pro: right-click a folder in Places → Save Place As.
2. Drop the `.kml` or `.kmz` on the box above, or press Choose a file. No file at hand? Open the sample.
3. Check the map and the notes: image overlays and network links are counted there, because GeoJSON can’t hold them.
4. Press Download GeoJSON for a `.geojson` file, or Copy GeoJSON to paste the FeatureCollection into your code.
5. Load it in Leaflet with `L.geoJSON(data)`, add it as a MapLibre `geojson` source, or import it into a Spatibase project.

## Formats and limits
- **Opens:** .kml or .kmz, up to 50 MB. Other map files (KML, KMZ, GPX, GeoJSON, shapefile, CSV) convert too.
- **Downloads:** GeoJSON, CSV of the same features.
- **Privacy:** the file is read in your browser and never uploaded.
- Try it with a sample: https://spatibase.com/tools/kml-to-geojson/?sample=1
- Download the sample file (the one Open a sample opens): https://spatibase.com/tools/samples/barcelona.kml

## What the GeoJSON keeps from your KML
| What | What happens |
|---|---|
| Points, lines, polygons | GeoJSON `Point`, `LineString` and `Polygon`, holes included, in the same longitude and latitude. |
| MultiGeometry | A `GeometryCollection`, even when every part is the same kind. Some tools, the Spatibase importer among them, take only `MultiPoint`, `MultiLineString` or `MultiPolygon`. |
| Altitude | Kept as a third coordinate. My Maps writes `0` everywhere, so its files come out as `[lng, lat, 0]`. |
| Name and description | `name` and `description` properties. HTML in a description becomes plain text, so links and images in it are lost. |
| Folders | A `folder` property with the path, such as `Trip / Day 1`. The features themselves are one flat list. |
| ExtendedData | One property per field. Plain `<Data>` values are strings (`"1.3"`); typed `SchemaData` keeps numbers as numbers. |
| Styles | Properties: `fill`, `stroke`, `stroke-width`, `fill-opacity`, `icon`, `icon-color` and the like, plus `styleUrl`. |
| Placemark id | The feature’s `id`. |
| Times | A `<TimeStamp>` becomes a `timestamp` property and a `<TimeSpan>` a `timespan` with `begin` and `end`. A `gx:Track` keeps its point times in `coordinateProperties.times`. |
| Image overlays and network links | Skipped, with a count in the notes. Linked data online isn’t fetched. |
| Icons and photos inside a KMZ | Not included. The `icon` property keeps the path, such as `images/icon-1.png`, which no longer points anywhere. |

## KML and GeoJSON: same coordinates, different model
**No reprojection needed.** Both formats store WGS 84 longitude, latitude and optional altitude. The text `2.174356,41.403629,0` in a KML becomes the array `[2.174356, 41.403629, 0]`, number for number.

What changes is how the data around the coordinates is organised:

- **Folders flatten.** KML nests placemarks in folders; a GeoJSON FeatureCollection is one list. The path survives as the `folder` property, so you can filter on it.
- **Styles become properties.** KML keeps colours in shared `<Style>` blocks. togeojson copies them onto every feature as simplestyle keys, which geojson.io draws as they are and MapLibre can use in data-driven paint.
- **Values arrive as strings.** A KML `<Data>` value is text, so `1.3` reads as `"1.3"`. Only a `<Schema>` with a type keeps numbers; convert the others with `Number()` or in QGIS.

**Need a lean file?** Style keys and `styleUrl` add bytes to every feature. Delete what you don’t draw before shipping it to a browser, and check the result with the GeoJSON validator on this site if another tool refuses it.

## Convert KML to GeoJSON in JavaScript
@tmcw/togeojson, the library this page uses, works in the browser and in Node.js. It needs a parsed XML document:

```js
import { kml } from '@tmcw/togeojson'
import { DOMParser } from '@xmldom/xmldom' // only in Node.js; browsers have DOMParser

const doc = new DOMParser().parseFromString(kmlText, 'text/xml')
const geojson = kml(doc) // a FeatureCollection
console.log(geojson.features.length)
```

**Watch the descriptions.** A CDATA description comes back as an object `{ "@type": "html", value }`, not a string. This page turns it into plain text; your code should do the same or render it carefully.

**For a KMZ,** unzip it first, for example with fflate’s `unzipSync`, and pass `doc.kml` (or the first `.kml` in it) to `kml()`. Use `kmlWithFolders()` instead of `kml()` to keep the folder tree.

## Frequently asked questions
### How do I convert KML to GeoJSON in JavaScript?
Parse the KML with DOMParser (xmldom in Node.js) and pass the document to kml() from @tmcw/togeojson. It returns a FeatureCollection. For a KMZ, unzip it first and read the doc.kml inside.

### Why does the GeoJSON have fill, stroke and styleUrl properties?
They are the KML’s styles. togeojson copies each placemark’s colours and icon onto its feature as simplestyle properties, which geojson.io and other simplestyle-aware tools draw directly. Delete them if your map styles the data itself.

### Are KML folders kept in GeoJSON?
As a property, not as structure. GeoJSON has no folders, so all placemarks go into one FeatureCollection and each feature gets a folder property with its path, such as Trip / Day 1. Filter on it to rebuild the groups.

### Why are my ExtendedData numbers strings in the GeoJSON?
KML Data values are plain text, so a value like 12 arrives as "12". Fields declared in a Schema with a type such as int or double stay numbers. Convert the rest in your code, or fix the types after importing.

### Why do my GeoJSON coordinates have a third number?
It is the altitude from the KML. Google My Maps writes 0 for every point, so its files give [longitude, latitude, 0]. RFC 7946 allows a third value and web maps ignore it, so you can leave it or strip it.

### Can I convert a Google My Maps KMZ to GeoJSON?
Yes. The KMZ is unzipped in your browser and the KML inside is converted, with every layer’s places and your table columns. The marker icons packed in the KMZ aren’t part of the GeoJSON.

## Next step
Turn the file into a live map your team can edit: **Save to Spatibase (free)** on the page saves it to a free Spatibase project (https://app.spatibase.com/signup), your places on a map you can edit and a live GeoJSON address for your site. Or download the GeoJSON and import it by hand (https://spatibase.com/docs/content/import/).