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Convert CSV to TopoJSON
Turn CSV / delimited text into TopoJSON instantly in your browser. No upload, no account, and no file ever crosses the network.
About CSV / delimited text
Delimited table with lon/lat columns, a WKT geometry column, or both.
- With lon/lat output, non-point geometries are written as their centroid.
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 CSV to TopoJSON
- 01
Drop your .csv file
Open the converter and drop the CSV / delimited text 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.
CSV to TopoJSON — questions
Is converting CSV to TopoJSON really private?
Yes. The conversion runs entirely in your browser using a Web Worker — the CSV / delimited text file is never sent to a server, so it works with confidential data and offline.
Do I need an account to convert CSV 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 CSV