utkalsharma
- Aug 13
- 2 min read

What are the differences between KML and KMZ files?

Updated: Sep 4

A KML (Keyhole Markup Language) file is a file format designed to display geographic information in applications like Google Earth, Google Maps, and other GIS applications. These files are XML-based and can incorporate a variety of geographical elements, including locations, paths, polygons, images, and even 3D models. Additionally, KML files can define styles that control the appearance of the data, such as line colors, icon designs, and more.

A KMZ file is a compressed version of a KML file. The "Z" in KMZ stands for "Zipped," as the file is compressed to reduce its size, making it more convenient to share. A KMZ file can contain not only the KML data but also any associated files, such as images, 3D models, or custom icons, all packaged together in a single file. When opened in an Earth browser or GIS application, the contents are automatically extracted and displayed.

What are the differences between KML and KMZ files?

The primary difference between KML and KMZ files lies in their format and how they handle additional data:

File Format

KML files are XML-formatted plain text files used to define geographical data such as points, lines, and polygons for mapping applications like Google Earth and Google Maps.
A KMZ file is a compressed (zipped) version of one or more KML files. The letter "Z" denotes that the file is zipped. KMZ files are typically smaller in size compared to KML files.

Handling Additional Data

A KML file only contains XML code that describes geographic features and elements. If you want to include images, custom icons, or 3D models, you need to share those files separately. The KML file would reference them via links or paths.
A KMZ file can package a KML file with all associated resources like images, icons, or 3D models into a single compressed bundle. This simplifies sharing and distributing all required files without concerns about missing external resources.

Usage

KML: Primarily used when sharing textual geographic data without additional resources or when the resources are already available online and referenced by URLs.
KMZ files are the preferred choice when you need to combine all elements into a single file, ensuring that everything, including custom icons or images, is included and easily shareable. KMZ files are also more convenient for storage and distribution due to their smaller size.