Skip to the converter

KML to TopoJSON converter, without the upload.

Turn KML map files into TopoJSON. It is converted in your browser, so the file never leaves your device.

Drop KML files here

or choose from your computer paste with Ctrl V

Ready · other file types work too0 bytes uploaded, ever

Convert to

How to convert KML to TopoJSON

  1. Add your KML map files

    Drop KML files onto the box above, or click it to choose them. ToAny reads the file's contents to detect the type, so a wrong extension does not matter.

  2. TopoJSON is already chosen

    Press Convert. There is nothing else to set. The work happens in this tab.

  3. Download

    Save the TopoJSON, or download everything as one ZIP if you converted several files.

Why ToAny

  • Private by construction

    The KML to TopoJSON converter is part of this page and runs inside your browser. Your map files are never sent to ToAny or to anyone else.

  • No upload, no queue

    Nothing has to travel to a server and back, so the conversion starts the moment you press Convert, even on a slow connection.

  • Free, without an account

    No sign-up, no email address and no watermark. Add several files and download them together as a ZIP.

KML to TopoJSON: what to expect

KML is XML tied to Google Earth's way of styling, and not all GIS tools read every feature. TopoJSON is much smaller than GeoJSON for adjacent regions. KML is at home in places, routes and tours viewed in Google Earth; TopoJSON is the usual choice for compact boundary maps for the web.

Every format is read into plain GeoJSON features and written out from there, so coordinates, names and properties carry over wherever the target has a place for them. XML that declares custom entities is refused, and KML files are parsed without touching the network. Coordinates are kept exactly (no quantisation) and shared borders are stored once; features without a shape are left out.

KML vs TopoJSON

KML

KML map file

KML is the format of Google Earth. It stores placemarks, lines and areas with names, descriptions and styling in XML, and can add camera paths for tours. It became an Open Geospatial Consortium standard in 2008. A KMZ is the zipped form.

Opens in Google Earth, Google My Maps, QGIS and most GIS tools

KML converter
TOPOJSON

TopoJSON map data

TopoJSON is an extension of GeoJSON that encodes shared borders once, as arcs, instead of repeating them in every neighbouring shape. Maps of countries or counties come out far smaller. Libraries such as D3 read it, and many general GIS tools need it converted first.

Opens in D3, Mapshaper, QGIS and web mapping libraries

TopoJSON converter
KML compared with TopoJSON
KMLKML map fileTOPOJSONTopoJSON map data
Stands forKeyhole Markup LanguageTopoJSON
TypeGeographic dataGeographic data
CompressionNone (XML text)None (JSON text, topology-encoded)
Introduced2004, by Keyhole, later Google (now an OGC standard)2012, by Mike Bostock
Opens inGoogle Earth, Google My Maps, QGIS and most GIS toolsD3, Mapshaper, QGIS and web mapping libraries
Best forPlaces, routes and tours viewed in Google EarthCompact boundary maps for the web
File extension.kml.topojson

Questions

Are my map files uploaded anywhere?

No. The KML to TopoJSON conversion runs inside your browser, on your own phone or computer. The file is not sent to ToAny or to anyone else.

Is anything lost when converting KML to TopoJSON?

The values are kept. Anything TopoJSON has no way to express, such as formatting, formulas or nesting, is simplified or left out.

Can I convert several KML files at once?

Yes. Add as many as you like, convert them together and download each result or all of them as one ZIP.

How do I convert KML to TopoJSON on Windows, Mac, iPhone or Android?

The steps are the same everywhere because ToAny runs in the web browser: open this page in a current version of Chrome, Edge, Safari or Firefox, add the KML file, press Convert and save the TopoJSON. There is nothing to install.

Is there a file size limit?

Yes. Files up to 150 MB are accepted; a larger file is refused with a message. Beyond that the limit is your device's memory, since nothing is uploaded; a computer copes with large files better than a phone.