KMZ File — What It Is, How to Open It, Convert to GPX

A KMZ file is almost always a ZIP archive that contains a KML document—commonly named doc.kml—and optionally images, icons, or other overlays referenced by that KML. Think of KMZ as “KML packed for sharing,” not as a different way of measuring latitude and longitude.

This page owns the packaging story. For what KML markup means, see What is a KML file?. For a short side-by-side, see KML vs KMZ.

What a KMZ file is

Google Earth’s ecosystem needed a way to ship a map and its custom icons or ground overlays as one attachment. KMZ solves that by zipping the .kml together with supporting files. Many Earth “Save Place As” flows default to KMZ for exactly that reason.

You can rename a .kmz to .zip and open it with any normal unzip tool. Inside you should find at least one KML file. The conventional entry point is doc.kml at the root of the archive; relative links inside that KML point at sibling folders such as files/ or images/.

KMZ vs KML (packaging only)

KMLKMZ
On diskPlain .kml XML text.kmz ZIP container
Typical contentsMarkup onlydoc.kml + optional images/overlays
Same geography model?YesYes (the KML inside)

There is no separate “KMZ coordinate system.” Once you extract or parse the inner KML, you are back in ordinary KML territory (including the longitude-latitude coordinate order).

What’s inside the zip

A simple KMZ:

my-tour.kmz
├── doc.kml
└── files/
    └── icon.png

A complex one may add collada models, multiple overlays, or nested folders. For GPS conversion you usually care only about placemarks and LineString / track-like geometry inside doc.kml. Fancy overlays rarely map into GPX.

How to open a KMZ

  1. Google Earth — open the .kmz directly; Earth unpacks it for you.
  2. Google My Maps — import where size and feature limits allow.
  3. Unzip manually — rename to .zip or use unzip, then open doc.kml as in the KML guide.
  4. Convert for GPS apps — open in /kmz-viewer or convert with /convert/kmz-to-gpx when you need a .gpx for a watch or trail app.

Extracting the KML if you need to

When a tool only accepts .kml:

  1. Unzip the KMZ.
  2. Locate doc.kml (or the sole .kml if named differently).
  3. If the KML references local images with relative paths, keep the folder layout if you still need those visuals in Earth.
  4. For GPS conversion, the standalone KML geometry is usually enough—pass either the KMZ or the extracted KML to /convert/kml-to-gpx.

Broken KMZ files are often truncated downloads or archives that somehow lost doc.kml. Unzipping is the fastest way to see which.

Convert KMZ / KML → GPX for apps and watches

GPS watches and hiking apps want GPX, not Earth packages:

  1. Go to /convert/kml-to-gpx.
  2. Drop the .kmz or .kml.
  3. Save the GPX and optionally inspect it before syncing.

Going back toward Earth after editing a track: clean up in a GPX editor, then /convert/gpx-to-kml, and re-zip in Earth if you need a KMZ again.

Common gotchas with KMZ

KMZ on phones and tablets

Mobile Google Earth and Maps apps vary in how cheerfully they import KMZ. If a phone refuses the file:

  1. Try opening it in desktop Earth once to confirm the archive is valid.
  2. Convert to GPX with /convert/kml-to-gpx and open the GPX in a trail app or /gpx-viewer.
  3. If you still need Earth features (overlays), keep the KMZ for desktop and use GPX for the GPS device.

Privacy note

A KMZ can embed photos of houses, vehicles, or private land as overlays. Browser converters on this site read the file locally, but you should still treat shared KMZ downloads as you would any archive from the internet: open from people you trust, and strip imagery you do not mean to redistribute.

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