100% local — files never leave your device
Convert KML to TopoJSON
Turn KML into TopoJSON instantly in your browser. No upload, no account, and no file ever crosses the network.
About KML
Google Earth / Maps markup with attributes in ExtendedData.
- KML is always written in EPSG:4326, as required by the specification.
About TopoJSON
Quantized topology used by D3 and web cartography.
- Export quantizes coordinates and writes one arc per ring; arcs are not deduplicated.
Step by step
How to convert KML to TopoJSON
- 01
Drop your .kml file
Open the converter and drop the KML file — parsing happens locally in a Web Worker, so nothing is uploaded.
- 02
Choose TopoJSON as the output
Pick TopoJSON, reproject to any of 180+ coordinate systems if needed, trim attributes and preview the geometry on a map.
- 03
Download the .topojson file
Save a single file, or convert a whole batch and download everything as a ZIP. Nothing is stored after the download.
KML to TopoJSON — questions
Is converting KML to TopoJSON really private?
Yes. The conversion runs entirely in your browser using a Web Worker — the KML file is never sent to a server, so it works with confidential data and offline.
Do I need an account to convert KML to TopoJSON?
No. There is no signup, no email and no install. Open the converter, drop the file and download the result.
What happens to attributes and coordinate systems?
Export quantizes coordinates and writes one arc per ring; arcs are not deduplicated. You can also reproject between 180+ coordinate reference systems or add a custom proj4 definition before writing.
Need the other direction? Convert TopoJSON to KML