Converting KMZ to KML extracts the plain-text Google Earth document from its compressed ZIP container.
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.
What is KML?
KML (Keyhole Markup Language) is an XML-based format for expressing geographic annotation and visualization, adopted as an OGC standard and popularized by Google Earth.
KML describes Placemarks, geometries (points, lines, polygons), and their presentation using an XML tree that also supports folders for organization, rich styling (icons, colors, line widths, fills), balloon descriptions, and ground overlays. It is designed for display and sharing rather than analysis, and is opened natively by Google Earth, Google Maps, and most GIS packages. Because it targets a single global view, it has no concept of reprojection.
Why convert KMZ to KML?
A plain KML is useful when you want a human-readable, text-editable file you can inspect, tweak, or diff in version control. Some tools and pipelines expect an uncompressed .kml rather than an archive. This conversion simply decompresses the package back to its source document.
Coordinate systems
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.
KML coordinates are always geographic WGS84 longitude, latitude, and (optionally) altitude in that order; the format has no CRS or projection field, so any data written to KML is expressed in EPSG:4326 by definition.
What to watch out for
- This is essentially decompression: the KMZ is unzipped and its doc.kml is returned unchanged.
- Coordinates remain WGS84 (EPSG:4326); nothing is reprojected.
- Only the main KML document is emitted; any bundled icons or images in the archive are separate assets, not part of the KML text.
- The resulting KML is larger on disk than the compressed KMZ.
How to convert KMZ to KML
- Drag your KMZ file (.kmz) into the converter above, or click to browse.
- Confirm the source is KMZ and choose KML as the output format.
- Optionally pick a target coordinate system (EPSG) to reproject.
- Click Convert and download your KML file. Everything runs in your browser.
Frequently asked questions
- Is any data lost extracting KML from KMZ?
- The geometry and attributes are identical; you are simply unzipping to the underlying doc.kml.
- What about images packed in the KMZ?
- The KML itself is the document; assets bundled alongside it are separate files inside the archive and are not part of the .kml text.
- Why would I want KML instead of KMZ?
- KML is plain text, so it is easy to open in an editor, inspect, edit, and track in version control.