Free online KML to KMZ converter

Source format

KML stands for Keyhole Markup Language. It is an XML-based format used to describe geographic data such as placemarks, paths, polygons, overlays, and camera views. KML is widely used by Google Earth, GIS tools, mapping platforms, and custom location-based applications. It is especially common for sharing map annotations, route data, and simple geospatial visualizations.

Target format

KMZ is the compressed version of KML. A KMZ file is essentially a ZIP archive that usually contains a KML file plus any linked resources such as images, icons, or overlays. The main advantages of KMZ are smaller file size, easier distribution, and better portability when a KML project depends on external assets. KMZ is also widely supported by Google Earth and many GIS viewers.

How to perform the conversion

The simplest way to convert KML to KMZ is to package the KML file into a ZIP archive and rename the archive with the .kmz extension. The archive should contain the main .kml file at the top level, and any referenced local assets if needed.

1. Make sure your KML file is valid and opens correctly in a KML-compatible viewer.
2. If the KML references local images, icons, or overlays, place those files in the same folder structure you want preserved inside the archive.
3. Create a ZIP archive containing the .kml file and any related resources.
4. Rename the archive from .zip to .kmz.
5. Open the resulting KMZ in Google Earth or another compatible application to verify that it loads correctly.

If you prefer desktop software, Google Earth Pro can open KML files and save or export them in KMZ form. In many cases, you can use File → Open to load the KML, then File → Save Place As and choose KMZ as the output format. Some GIS tools and KML editors also provide direct export to KMZ.

You can also convert the file on 101convert.com for free, without installing any software.

Notes on quality and compatibility

KML to KMZ conversion does not change the geographic content; it mainly changes how the data is packaged. However, compatibility depends on how the KML is structured. If the KML uses external links to images or other resources, those files should be included in the KMZ or the content may not display correctly. Absolute web URLs usually continue to work, but local file references may break if they are not packaged properly.

KMZ is best for sharing complete map projects, while plain KML is often better for editing and version control because it is human-readable. If your KML is very large, KMZ can reduce transfer size significantly, but the compression ratio depends on the amount of text and embedded assets. Some older or limited viewers may support KML better than KMZ, so test the output in your target application if compatibility is important.