KML to TopoJSON Converter
Convert KML (.kml) files to TopoJSON (.topojson) right in your browser — free, instant and private. Drop a file below and download the result in seconds. Nothing is uploaded to a server, so your data never leaves your device.
Drag & drop your .kml file
or click to browse
How to convert KML to TopoJSON
- 1
Add your KML file
Drag and drop your .kml file onto the box above, or click to browse — you can also paste the raw text directly.
- 2
Convert in your browser
GeoMaps reads the KML and rewrites it as TopoJSON locally, on your device. The conversion is instant and your file is never sent anywhere.
- 3
Download your TopoJSON
Click download to save the converted .topojson file, or copy the output text. That's it — no account, no watermark, no limits.
KML (Keyhole Markup Language) is an OGC standard XML format created for Google Earth and used widely across Google Maps, mobile mapping apps and GIS software. It stores placemarks, paths, polygons, styling and folder structure, which makes it ideal for sharing annotated maps with non-technical audiences. A KML file is plain text; when zipped with its assets it becomes a KMZ.
Need the other direction instead? TopoJSON is a compact GeoJSON extension that encodes shared topology. TopoJSON is an extension of GeoJSON that encodes topology: shared boundaries between features are stored once as 'arcs' instead of being duplicated. The result is dramatically smaller files — often 80% smaller than the equivalent GeoJSON — which makes it popular for web visualizations (notably D3.js) where download size matters. It converts losslessly back to GeoJSON for editing.
What is KML?
.kmlKML (Keyhole Markup Language) is an OGC standard XML format created for Google Earth and used widely across Google Maps, mobile mapping apps and GIS software. It stores placemarks, paths, polygons, styling and folder structure, which makes it ideal for sharing annotated maps with non-technical audiences. A KML file is plain text; when zipped with its assets it becomes a KMZ.
What is TopoJSON?
.topojsonTopoJSON is an extension of GeoJSON that encodes topology: shared boundaries between features are stored once as 'arcs' instead of being duplicated. The result is dramatically smaller files — often 80% smaller than the equivalent GeoJSON — which makes it popular for web visualizations (notably D3.js) where download size matters. It converts losslessly back to GeoJSON for editing.
KML to TopoJSON — FAQ
- How do I convert KML to TopoJSON?
- Upload your .kml file using the converter above (drag & drop or click to browse). GeoMaps converts it to TopoJSON instantly in your browser and gives you a .topojson file to download. No software to install and no signup required.
- Is the KML to TopoJSON converter free?
- Yes — it's completely free with no usage limits, watermarks or account needed. We offer it as a free tool from GeoMaps, the platform for turning your data into interactive maps.
- Is my data private? Are my files uploaded to a server?
- No. The conversion runs entirely in your web browser using JavaScript — your file is never uploaded to any server. Because nothing leaves your device, it's safe for sensitive or confidential data and works even offline once the page has loaded.
- Can I convert TopoJSON back to KML?
- Yes. Use our TopoJSON to KML converter for the reverse conversion — every format on GeoMaps converts both ways.
- How large a file can I convert?
- Because conversion happens in your browser, the limit is your device's memory rather than a server quota — files up to tens of megabytes convert comfortably on a typical laptop. Very large datasets may be slower depending on your machine.