Key differences
| Criterion | KML | KMZ |
|---|---|---|
| Container | A standalone XML text document | A ZIP archive containing KML and optional assets |
| File size | Uncompressed and often verbose | Compressed; KML text commonly shrinks substantially |
| Supporting assets | Usually referenced as separate local files or URLs | Can bundle icons, images, textures and models inside one archive |
| Editing | Open directly in a text or XML editor | Unzip first to edit the contained KML and assets |
| Coordinates and features | WGS 84 placemarks, geometry and styling | The same KML content model and WGS 84 coordinates |
| Google Earth support | Opens directly | Opens directly and is commonly used for distribution |
When to choose KML
Small datasets, hand editing, debugging XML, source control and cases where external assets are unnecessary or already hosted online.
When to choose KMZ
Sharing larger Google Earth projects, compressing verbose KML and keeping custom icons, images, overlays or 3D models together.
Conversion and migration checks
- Use relative paths for assets that will be bundled inside a KMZ archive.
- Keep one main KML document in the archive so readers consistently find the intended file.
- After converting KMZ to KML, remember that bundled icons and images become separate files and may need new paths.
- Choose KMZ for delivery and KML for editing; converting between them does not reproject coordinates.
Convert between KML and KMZ
Read the format guides
Frequently asked questions
- Is KMZ the same as KML?
- KMZ contains KML, but it is not the same file type. It is a compressed ZIP archive that packages a main KML document with zero or more supporting files.
- Can Google Earth open both KML and KMZ?
- Yes. Google Earth opens both directly. KMZ is especially useful when a project contains images, icons, models or a large KML document.
- Does converting KML to KMZ change coordinates or styling?
- No. The KML content remains the payload, so its WGS 84 coordinates, placemarks and styling stay the same. The conversion mainly adds ZIP compression and asset packaging.