A KMZ file stores map data and imagery in a compressed format that Google Earth and similar programs can read

A KMZ file is a compressed folder that holds map information — usually placemarks, paths, polygons, and satellite images — in a format called KML (Keyhole Markup Language). When you download a map from Google Earth or share location data with someone else, you are often working with a KMZ file. The "Z" stands for the compression method used: the file is essentially a zipped folder that your computer unpacks when you open it.

KMZ files are text-based underneath the compression, which means they are human-readable if you extract them, but most people never need to look inside. You open them the same way you open any other file — by double-clicking or dragging them into an application that understands the format.

Key Takeaways

  • KMZ files contain map data, placemarks, and imagery compressed into a single file that Google Earth and similar programs can read.
  • You can open a KMZ file by double-clicking it if Google Earth is installed, or by dragging it into Google Earth, Google Maps, or other mapping software.
  • KMZ files are created when you save or export maps from Google Earth, or when someone shares location data with you as a downloadable file.
  • If you need to edit the contents of a KMZ file, you can extract it using standard file compression software and edit the KML text inside.

How to open a KMZ file on Windows or Mac

The easiest way is to install Google Earth (the free desktop version) and double-click the KMZ file. Google Earth will launch automatically and display the map data. If Google Earth is already installed, this usually happens without any extra steps.

If you do not have Google Earth installed, you can drag and drop the KMZ file directly into Google Maps in your web browser. Open Google Maps, click the menu icon (three horizontal lines) in the top left, select "Your places," then click "Maps." From there, you can create a new map or open an existing one and import the KMZ file by clicking the import button.

Other programs that read KMZ files include ArcGIS (professional mapping software), QGIS (free and open-source), and Garmin BaseCamp (for GPS devices). Mobile apps like Google Earth for Android and iOS also open KMZ files if you download them to your phone and tap them.

What information a KMZ file typically contains

A KMZ file usually holds placemarks (individual points on a map with names and descriptions), paths or routes (lines connecting multiple points), and polygons (shaded areas representing regions or boundaries). It can also include satellite imagery, ground overlays, and 3D models of buildings or terrain.

Each placemark can have a name, description, and custom icon. Paths and polygons can have different colors and line styles. When you open the file in Google Earth, all of this information displays exactly as the person who created it intended.

The file size depends on how much data is inside. A simple map with a few placemarks might be a few kilobytes. A detailed map with satellite imagery and 3D models can be several megabytes.

How KMZ files are created and shared

You create a KMZ file by saving or exporting a map from Google Earth or Google Maps. In Google Earth, you right-click a placemark, path, or folder and select "Save as KMZ." In Google Maps, you open a custom map, click the menu, and select "Export to KML/KMZ."

People share KMZ files when they want to send you a map they have created — for example, a hiking route, a real estate tour, a list of restaurants, or a property boundary. Instead of describing the locations in words or sending screenshots, they send the KMZ file, and you can open it in your own copy of Google Earth or Maps to see exactly what they see.

KMZ files are also used by GPS device manufacturers and surveying software. If you own a Garmin GPS unit, you can export routes and waypoints as KMZ files and transfer them between devices.

Extracting and editing the contents of a KMZ file

If you need to edit the data inside a KMZ file, you can extract it using any standard file compression software — 7-Zip (free, Windows), WinRAR (Windows), or the built-in Archive Utility on Mac. Right-click the KMZ file, select "Extract" or "Unzip," and the folder will open.

Inside you will find a file called doc.kml (or sometimes a folder structure with multiple files). The KML file is plain text written in XML format. You can open it in any text editor — Notepad on Windows, TextEdit on Mac, or any code editor — and edit the coordinates, names, descriptions, and colors directly.

After you make changes, save the KML file, then compress the folder back into a KMZ file by right-clicking and selecting "Send to > Compressed (zipped) folder" on Windows, or "Compress" on Mac. This approach is useful if you are working with large datasets or need to batch-edit many placemarks, but for most people, editing inside Google Earth or Google Maps is simpler.

Common reasons you might receive a KMZ file

Real estate agents send KMZ files showing property listings and neighborhood information. Urban planners and architects share site maps and development proposals. Hikers and outdoor enthusiasts share trail routes and waypoint collections. Researchers and scientists use KMZ files to share geographic data, survey results, and field observations.

If someone sends you a KMZ file and you do not have Google Earth installed, the fastest solution is to open Google Maps in your browser and import it there. You do not need to install anything or create an account beyond what you already have if you use Google services.

KMZ vs. other map file formats

KMZ is Google's standard format, but other mapping programs use different formats. GPX (GPS Exchange Format) is common for GPS devices and fitness trackers. GeoJSON is used in web mapping and data science. Shapefile is the standard in professional GIS software. GeoTIFF is used for satellite imagery and raster data.

If you receive a file in a different format and need to convert it to KMZ, most mapping software can import and re-export to different formats. Google Earth can open GPX files and save them as KMZ. QGIS can convert between almost any geographic format. Online conversion tools also exist, though you should be cautious about uploading sensitive location data to unfamiliar websites.

Frequently Asked Questions

Can I open a KMZ file without installing Google Earth?

Yes. You can import it into Google Maps in your web browser, or use free software like QGIS or Garmin BaseCamp. Mobile versions of Google Earth also open KMZ files if you download them to your phone.

Is a KMZ file safe to open?

KMZ files are just compressed map data and do not execute code, so they cannot install malware or viruses. However, like any file from an unknown source, use common sense: only open KMZ files from people or organizations you trust.

Can I edit a KMZ file directly without extracting it?

Not directly. You must extract it first to access the KML file inside. However, you can open the KMZ file in Google Earth or Google Maps and edit the placemarks, paths, and colors there, then save the changes as a new KMZ file.

What happens if I rename a KMZ file to ZIP?

It will work. KMZ files are ZIP archives, so renaming the extension from .kmz to .zip lets you extract it with any file compression software. Renaming it back to .kmz afterward will not change how it works.

Can I convert a KMZ file to a different format?

Yes. Google Earth can export to KML (uncompressed). QGIS, ArcGIS, and other GIS software can convert KMZ to GPX, GeoJSON, Shapefile, and other formats. Online conversion tools also exist for simpler conversions.