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GPX to KMZ Converter
Turn .gpx tracks into .kmz files — the single, self-contained package Google Earth opens by default. Track, elevation and timestamps are packed into a standards-compliant KMZ built right in your browser; nothing is uploaded anywhere.
How to convert to KMZ
- 1
Drop your file
Drag a FIT, GPX, TCX, KML, KMZ or GeoJSON file onto the box above, or click it to browse. The source format is detected automatically from the file contents.
- 2
Wait a beat
The conversion runs in a background worker on your device. Typical activities finish in well under a second; even 50 MB files process without freezing the page.
- 3
Check the preview
Distance, duration, ascent and average heart rate are shown alongside a map of the converted track, so you can confirm nothing was lost before downloading.
- 4
Download
Click the download button and the .kmz file is saved straight from memory. Nothing was uploaded, so there is nothing to clean up.
What is a GPX file?
GPX (GPS Exchange Format) is the universal, open XML format for GPS data, standardized by TopoGrafix and supported by essentially every mapping application on earth — Strava, Google Earth, Komoot, RideWithGPS, Garmin BaseCamp, QGIS and hundreds of others. A GPX file stores waypoints, routes and tracks as latitude/longitude pairs, optionally with elevation and timestamps, and Garmin's TrackPointExtension carries heart rate, cadence and power alongside each point.
Because GPX is plain text XML, it is readable, diffable, scriptable and trivially editable — which makes it the lingua franca when a track needs to move between ecosystems. The cost is size: the same activity as GPX is typically 5-10× larger than FIT, and consumer-oriented apps sometimes ignore the extension channels. For archiving, editing and cross-platform sharing, though, GPX remains the safest long-term bet.
What is a KMZ file?
A KMZ file is a KML file zipped: a standard ZIP archive containing a doc.kml plus whatever resources the map references — custom icons, photos, terrain overlays. Zipping is what Google Earth does by default when it exports a map, because a folder of linked files is awkward to email and a single self-contained package is not. Everything Earth can express in KML travels inside the one .kmz file.
Most tools that say they read KML also read KMZ, but plenty of workflows stumble on the zip layer: text editors, diff tools, scripts that expect XML, and web uploaders that only accept a plain .kml. Unpacking a KMZ — or packing one for distribution — is a two-step chore this site does in the browser: the archive is opened and the KML inside is parsed on your device, with no unzip utility required.
Why package a track as KMZ?
KMZ is what Google Earth hands you when you export a map, and what it (along with most GIS software) opens most readily from email attachments and downloads. For sharing a route with a group — a club ride, a race briefing, a travel itinerary — one .kmz attachment beats a .kml plus a readme plus a folder of icons. Recipients double-click; the route appears on the globe; nobody installs anything beyond Earth itself.
The packaging also travels better through pipelines that mangle loose files: version control systems, chat clients and cloud drives sometimes treat .kml as text and 'helpfully' re-encode it. A .kmz stays a binary blob end to end, arriving byte-identical. And when the audience later wants the plain KML — to edit it or read it as text — any unzip utility (or this site's KMZ to GPX tool) opens the package in place.
What's inside the file this tool builds
The KMZ this page produces contains a doc.kml — the name every Earth-flavored tool looks for first — holding your track as standards-compliant KML 2.2. Recorded tracks with timestamps are written as gx:Track (time-slider playback works); drawn routes without them are plain LineStrings. Elevation carries over, and multiple track segments become separate placemarks.
Two honest notes. The package contains only the track KML — the original GPX's heart rate, cadence and power channels have no KML representation and are dropped. And the KMZ is written without compression (zip STORED method), which every reader accepts and keeps the build instant; the file is correspondingly larger than a maximally-zipped one, a fair trade for a format whose contents are already compact XML.
Your files never leave this browser
This tool — like every tool on this site — runs entirely as client-side JavaScript. The file you drop is parsed in a Web Worker on your own device, converted in memory and handed straight back to you as a download. There is no upload endpoint, no server-side conversion service and no temporary storage: you can watch the network tab in your browser's developer tools and confirm that no file bytes are transmitted anywhere.
That matters more with fitness data than with most files. A GPS track is a precise log of where you were, at what time, and how hard your heart was working — home address, training habits, favorite routes and race schedule all in one file. Keeping conversion on-device means third-party converters never get a copy of that log, and the tool keeps working identically on a plane, in a basement, or anywhere else without signal.
GPX vs KMZ at a glance
| Aspect | GPX | KMZ |
|---|---|---|
| Format type | GPS exchange XML | ZIP package containing KML |
| Typical use | Mapping apps, navigation | Self-contained Google Earth sharing |
| GPS + elevation | Yes | Yes (inside the KML) |
| Timestamps | Optional per point | gx:Track when present |
| Heart rate / power | Via TrackPointExtension | Not representable — dropped |
| Best for | Moving data between tools | One-file distribution to humans |
Frequently asked questions
KMZ is a KML file inside a standard ZIP archive, usually named doc.kml. The zip layer lets one file also carry icons, photos and models that the KML references. If you only need the geometry, KML and KMZ are interchangeable — every reader of one reads the other.