Map Files Explained: KML, KMZ, GPX and CSV in Google Maps, My Maps and Earth

Choose the destination before converting anything. Keep the original file, make a separate working copy, and reopen the result in the app your recipient will use. A successful upload does not guarantee that every point, photo, timestamp or folder survived.

Which map file format should you use?

Google Sheets is a cloud spreadsheet, not another filename extension. CSV is plain tabular text: it does not preserve spreadsheet formulas, multiple tabs or cell formatting. The table’s Earth export instructions are for a computer; do not assume a matching project-export menu on Android or iPhone/iPad.

KML and KMZ are closely related, not competing levels of quality. Choose KMZ when you need to bundle supporting resources, then check that they were actually included. Neither format promises identical presentation everywhere. Ordinary Google Maps is the viewer in these workflows, not the file importer or exporter.

Pick the right app first

Google Maps is for finding places and navigating. My Maps is the custom-map editor for importing a table or file into layers. Earth is for viewing geographic features on a globe, making projects and inspecting terrain. The Maps, My Maps and Earth comparison explains those boundaries.

Within Earth on the web, distinguish three destinations:

• Project features: supported editable features saved in a Drive project.
• Data layer: an imported dataset that can be styled, but whose source features cannot be directly edited one by one. You must own the destination project to import a data layer; editor access alone is not enough.
• Local KML: a device-local file, separate from a shared Drive project.

Earth Pro is the installed desktop application, with its own Places panel and GPS-import tools. Earth mobile has a Local project list, but you should not expect desktop menus there. Use the Earth web, Pro and mobile comparison before following instructions written for another version.

Move a spreadsheet into My Maps

For addresses, survey sites or a class collection of public places, start with a clean table rather than converting it to KML first.

1. Give the first row clear column headings. Include a name and a usable location: an address, place name, separate latitude/longitude fields or supported WKT geometry. For a WKT import, name that column WKT.
2. Keep a stable record ID if you will update the map later. Remove private information from the working copy.
3. On a computer, sign in to My Maps, open or create a map, and look for Add layer in the map legend.
4. Under that layer, look for Import and select your file or Google Sheet.
5. Follow the prompts to choose the location column or columns and the names for the features. For WKT, select the WKT column when offered.
6. Check several known locations and compare the imported table with the source.

For example, a fictional fieldwork table could use Site ID, Name, Latitude, Longitude and Observation. The observation explains the site; it should not be selected as a location field. The CSV, Excel and Sheets import guide walks through those choices.

A Sheet import is not a promise of continuous synchronization. My Maps provides deliberate reimport and merge operations. Back up before using them: Update matching items deletes existing features that do not match the incoming file. Choose the matching ID columns carefully.

Move a My Map into Google Earth

There are three different handoffs. Start on a computer.

For a portable file: in My Maps, look in the map-level menu for Export to KML/KMZ. Check the selected map or layer scope, download it, and open the download in Earth. The My Maps export guide covers whole-map files and individual-layer CSVs.

For a current view: look for View in Earth in the My Maps map-level menu. This opens a view-only representation; edit in My Maps and refresh the Earth view to see changes. A downloaded file is a separate handoff, so do not assume the same refresh connection.

For an editable Earth copy: in Earth web, look for New → Open My Maps from Drive. Select the map, then look for Copy to Map Project in the toolbar. Review the new project’s name and sharing settings. The original My Map stays untouched; the copy is a separate project.

When importing a downloaded KML/KMZ, choose project features if individual editing matters, or a data layer when the larger-dataset viewing workflow fits. For device-local inspection on a computer, look for Open local KML editor → Open KML from device. The guide to import KML into Google Earth explains those modes.

Bring a GPS track into Maps or Earth

You do not need to convert GPX before importing it into My Maps: GPX is a documented input.

Use a computer and look for Add layer → Import, then compare the imported path, waypoint names, start, finish and gaps between recorded segments. On Android or iPhone/iPad, sign in to Google Maps with the account that can access the map and look for You → Maps, then select it. The GPX import guide covers the device handoff.

A track is a sequence of recorded positions, not an instruction for Google Maps to navigate that exact line. If you request directions, Maps calculates a route separately. Check it against your intended journey; adding stops is a routing task, not a GPX conversion.

For recorded time or altitude, start with the original GPX in Earth Pro. Its import choices distinguish time-aware KML tracks from LineStrings without an associated time element. Avoid Adjust Altitudes to Ground Height when you want to inspect recorded altitude: it moves recorded points to ground level.

For Earth web or mobile, save a separate KML/KMZ from Pro and import that copy. Retain the GPX, especially if recording times, sensor fields or track segments matter.

Save an Earth project as a file

In Earth web on a computer, look for the project’s More menu on the home screen, or the corresponding action in the open project’s toolbar, then Export as KML file. Project owners can restrict downloading, copying and exporting for viewers and commenters; a shared view does not guarantee export permission.

For a local KML, explicitly Save or Download edits to your device. Autosave is supported only in Chromium-based computer browsers. Confirm that your saved copy reopens before closing the editor.

In Earth Pro, select the intended item or parent folder in Places, then right-click and look for Save Place As. Select KML or KMZ. Saving one placemark instead of its parent folder will not capture the rest of your collection. Follow the KML/KMZ creation guide for a complete export-and-reopen check.

On Earth for Android or iPhone/iPad, look for Local in the project list and New + to create or open local KML work. A local file is not automatically a shared Drive project. Keep a separate copy of important files rather than treating the local list as a cloud backup.

If you have legacy KML files stored inside Earth’s browser storage, Google says to download them or add them to map projects by 14 January 2027. That migration deadline is not a ban on opening device-local KML files.

Get coordinates into—and out of—a file

For a table, clearly label latitude and longitude separately. Preserve minus signs and identify the source coordinate system; do not relabel coordinates from a different system as WGS84. Google’s experimental Earth CSV/Sheets importer expects WGS84 decimal-degree coordinates and does not automatically detect a coordinate pair bundled into one cell. Split such pairs into separate columns before importing. Its CSV guidance also specifies UTF-8 encoding and comma separation.

For a location copied from Maps, use the Maps coordinates guide. If the place is not listed, drop a pin at the intended position rather than substituting a nearby named business.

Watch the order: Maps coordinate searches use latitude, longitude; KML coordinate tuples use longitude, latitude, with optional altitude. WKT also uses longitude before latitude for the geographic coordinates discussed here. The Google Earth coordinates guide explains the distinction.

To get data out of My Maps on a computer, look in the individual layer menu → Export data → CSV. Inspect the output before assuming it includes the coordinate fields or geometry representation you need. Keep the original coordinate table as well as a KML/KMZ when both tabular analysis and map geometry matter.

Earth Pro’s CSV import wizard is a separate workflow. Coordinates avoid relying on its address-geocoding coverage: Google’s Pro help documents address import only for the United States, United Kingdom, Canada, France, Italy, Germany and Spain. Do not apply that restriction to My Maps or assume that Earth Pro’s address importer works worldwide.

Limits and conversion losses to check

Google documents these separate My Maps constraints:

• Unzipped KML/KMZ: up to 5 MB; other supported files: up to 40 MB.
• Do not import files with more than 2,000 rows.
• A layer can hold 2,000 lines, shapes or places.
• A map can hold 10,000 lines, shapes or places, 50,000 total points within lines and shapes, and 20,000 data-table cells.

A compressed KMZ’s download size is not its unzipped size. A long track can also have few named features but many vertices. Splitting imports does not reset whole-map totals; do not interpret the spreadsheet row warning as a separately documented GPX track-point allowance.

For editable Earth web project features, Google describes limits of approximately 10,000 features or 250,000 vertices per project. Oversized KML/KMZ may fall back to a data layer, whose imported source features are not individually editable. Imported layers also use plan-dependent Earth storage and file-size allowances. These are not My Maps limits.

Before converting, decide what must survive:

Google specifically warns that My Maps KML imports may omit tours, time-based elements, image and screen overlays, MultiGeometries, 3D models, folders and information balloons containing HTML or JavaScript. Renaming a GPX or CSV extension to KML does not convert its contents. KMZ is not an offline copy of Google’s basemap.

Fix failed imports without risking the original

Start with the stage that failed, not a random converter.

1. No Import control: confirm you are in My Maps on a computer, using an account with edit access.
2. Anonymous uploads are not allowed: check the signed-in account, edit permission and whether My Maps can open Drive. Google documents the Drive-access check, but the error text alone does not prove one cause. Try a small, non-sensitive sample in a new map you own.
3. Immediate file rejection: check actual format, headers, file size and row count. A renamed HTML download is not a CSV.
4. Missing or misplaced features: inspect the source rows, selected location columns, coordinate order and address context.
5. Only the large file fails: investigate a copy for size, geometry complexity and unsupported content.

For “Anonymous uploads are not allowed,” follow the My Maps access checks before changing your file. The same guide covers other import failures. Do not make a private map public or bypass school or organization account policy to test an upload.

If the file opens but Earth’s imagery is blurry or absent, investigate Earth loading problems separately before rewriting the data.

Measure imported tracks and inspect elevation

An imported line, a calculated route and a terrain profile answer different questions. Use the distance and area comparison to choose the measurement tool rather than assuming every displayed line reports travel distance.

In Earth Pro, draw a path or open an existing one and look for Edit → Show Elevation Profile. In Earth web on a computer, Google also documents an elevation chart when drawing a line with the Path or polygon tool or the Measure tool. That does not promise the same controls for every imported track or for mobile.

The elevation-profile guide separates these workflows. Terrain elevation is not automatically the GPS device’s recorded altitude. Keep the original recording if you need to compare them.

Share a file or share a map?

Share the live map or project when people need the same maintained version. Send a file when they need an independent copy. A downloaded file can keep circulating after you restrict the original link.

Before sharing, open the actual outgoing file and inspect its names, descriptions, photos and precise locations. Remove student homes and identifying details from a shareable copy. The student-sharing guide explains view/edit access; the Maps privacy checklist covers separate account and sharing controls.

Include the filename, version date, intended app and any missing content in your handoff. For a class assignment, specify the required features and citations, as in the student map-project framework, rather than requiring a particular extension without explaining the result.

Common questions

Can Google Maps open a KML or GPX directly?

For the current workflow described here, use My Maps on a computer to import the file, then view that custom map in Google Maps. Pasting a filename into Maps search is not the import workflow.

Is KMZ better than KML?

KMZ is compressed and can include supporting files. It is convenient for a packaged handoff, but it does not guarantee better accuracy, complete media or universal feature support.

Can I export a whole My Map to CSV?

Google documents CSV export for individual layers, not the entire map. Use KML/KMZ for a whole-map geographic export and keep the source spreadsheet separately.

Can Google Earth import CSV or Google Sheets?

Current Earth web documentation lists experimental direct import as data layers, with automatic location detection. That is different from importing individually editable KML features. Check the offered mode and resulting locations. Earth Pro has its own CSV import wizard; importing a live Google Sheet is not the same desktop procedure.

Will an imported GPX give exact turn-by-turn directions?

Not through the display workflow described here. Google Maps calculates navigation separately. If exact-track following is essential, verify that capability in the navigation app you plan to use.

Is a saved Maps list the same as a My Map?

No. Labels, lists and Starred places are different saved objects. Use the saved-places comparison before looking for My Maps layer-export controls on a list.