What is KMZ and how is it different from KML?
KML and KMZ are often confused. KMZ is a compressed package that usually contains KML.
Field takeaways
- KML stores map geometry and style.
- KMZ is a compressed package.
- KML is enough for simple geometry.
- KMZ helps when packaging extra files.
- MapLab Survey can use KML/KMZ as field layers.
KML versus KMZ
KML carries points, lines, polygons and styling as XML text — you can open it in a text editor and read it. KMZ is a package: a compressed archive holding one KML file plus any icons, photos or overlay images. Technically a KMZ is a ZIP file — rename it to .zip and you will find doc.kml and the extras inside. That one sentence resolves most KMZ trouble.
When to use which
If you are sending pure geometry — a parcel line, a route, a boundary — KML is enough and produces the fewest surprises on the receiving end. If the file carries images, custom icons or several components, KMZ travels as a single attachment through email and WhatsApp, and nothing gets separated. Size also favours it: the same content is usually several times smaller as KMZ.
The coordinate fact
KML and KMZ always carry coordinates as WGS84 geographic (latitude/longitude). Your TUREF or UTM coordinates are converted on export; the receiving side converts back into whatever it needs. So "which coordinate system is this KMZ in?" has a fixed answer — the real question is whether the converting app did its job correctly.
Opening KMZ on a phone
MapLab Survey opens KMZ directly: import the file, name the layer, check its position against a known reference. From there the file is not just viewed — you add your own measurements, notes and photos over it, compute area and perimeter, and export the result again as KML/KMZ, DXF or CSV.
If a KMZ will not open: the checklist
The frequent causes, in order: the download is actually broken (be suspicious if the file is a few KB); the extension is wrong (some messaging apps turn .kmz into .zip — rename it back); the package has no doc.kml inside (the sender packed it wrong); or the file is simply huge and needs time. Renaming to .zip and looking inside is the fastest diagnosis.
Converting KMZ to KML
Two practical routes: open the KMZ in the app and export as KML, or rename to .zip and pull doc.kml out of the archive. The second leaves icons and images behind in the package — fine when geometry is all you need.
Try these steps on your own phone.
MapLab Survey handles RTK/GNSS point capture, drawing, area and volume calculations and coordinate conversion, then exports to DXF, KML/KMZ, GeoJSON, Shapefile, GeoPackage, NCZ or CSV. Capture, calculation and export work offline. Live NTRIP corrections and online basemaps need a connection.
Frequently asked questions
What is KMZ?
A compressed KML package.
Which is better?
KML for simple geometry, KMZ for packaged content.
Can KMZ open on a phone?
Yes.
Can parcels use KMZ?
Yes, as reference data.
Technical references
The field guidance in this article is aligned with the technical and official references below.
Related: Open KML file · Open KML on phone · Preparing KML for cadastre · MapLab Survey