What is GeoJSON?
GeoJSON is an open, JSON-based format for encoding vector geographic features and their attributes, standardized as RFC 7946 by the IETF.
A GeoJSON document is plain UTF-8 JSON built from Feature and FeatureCollection objects, each pairing a geometry (Point, LineString, Polygon, and their Multi* variants, or a GeometryCollection) with a free-form "properties" object. Because it is human-readable text, it works well with version control, text diffing, and any JSON tooling, and it is the de facto interchange format for web maps and JavaScript libraries such as Leaflet, Mapbox GL, and OpenLayers. Unlike Shapefile it imposes no field-name length limit, mixes geometry types freely within one collection, and stores everything in a single file.
What is KMZ?
KMZ is a ZIP archive that packages a KML document (conventionally named doc.kml) together with any assets it references, such as icons, images, and overlays.
Structurally a KMZ is just a compressed container: unzip it and you get a main doc.kml plus an optional folder of supporting files. Zipping typically shrinks verbose KML text substantially and keeps a placemark set and its custom icons together as one shareable file, which is why Google Earth exports KMZ by default. Everything true of KML applies to the KML inside a KMZ; the wrapper only adds compression and asset bundling.
Why convert GeoJSON to KMZ?
KMZ is the preferred way to email or share Google Earth data because compression can dramatically shrink verbose KML while keeping everything in one file. It is convenient for distributing large point or boundary sets to field teams and stakeholders. Google Earth reads KMZ natively and treats it just like KML.
Coordinate systems
Per RFC 7946, coordinates are longitude/latitude in decimal degrees on the WGS84 datum (EPSG:4326), and the specification removed the older "crs" member, so a compliant GeoJSON file is always assumed to be WGS84. Coordinate order is [longitude, latitude], optionally followed by elevation.
Because the payload is ordinary KML, a KMZ is inherently WGS84 (EPSG:4326) longitude/latitude/altitude, with no projection metadata and no possibility of reprojection inside the format.
What to watch out for
- The payload is WGS84 (EPSG:4326) KML. RFC 7946 or CRS-less GeoJSON already matches it; approved legacy named-CRS input is reprojected when necessary.
- A KMZ is a ZIP of a doc.kml, so it is essentially the KML conversion plus compression — the same styling and attribute limitations apply.
- GeoJSON properties become placemark attributes/description, not an analytical attribute table.
- Because it is compressed, a KMZ is not human-readable in a text editor the way GeoJSON is.
How to convert GeoJSON to KMZ
- Drag your GeoJSON file (.geojson, .json) into the converter above, or click to browse.
- Confirm the source is GeoJSON and choose KMZ as the output format.
- Optionally pick a target coordinate system (EPSG) to reproject.
- Click Convert and download your KMZ file. Everything runs in your browser.
Frequently asked questions
- What is the difference between KML and KMZ here?
- KMZ is simply a zipped KML. Choose KMZ for a smaller single-file doc.kml package; choose KML if you want a plain-text file.
- Can I unzip a KMZ to get the KML?
- Yes. A KMZ is an ordinary ZIP archive; unzipping it reveals the doc.kml inside.
- Are coordinates reprojected?
- RFC 7946 or CRS-less GeoJSON stays in WGS84 longitude/latitude. Approved legacy named-CRS GeoJSON is reprojected to WGS84.