County Maps US

Tools Map makers and file viewers

CSV to Map

The file is read in your browser and never uploaded. Coordinate columns are detected automatically; the rest of the row appears in the popup.

How to use it

  1. Drop a CSV file on the box or choose one. Comma, semicolon and tab separated files all work.
  2. Check the detected latitude and longitude columns, or pick them yourself, then press Plot.
  3. Choose a column to colour by and, optionally, one to size by. Click any point to read its row.
  4. Export the points as GeoJSON or KML.

How it works

The CSV is parsed in the browser with proper handling of quoted fields. Latitude and longitude are found first by header name (lat, latitude, y, lng, lon, longitude, x and their variants), then by value range when the headers are unhelpful. Rows without a valid coordinate pair are listed, not silently dropped.

A colour column with twelve or fewer distinct values gets one colour per value; a numeric column with more values gets a five-step ramp between its minimum and maximum. Up to 5,000 rows are plotted; the file must be under 8 MB. Addresses without coordinates are not geocoded here.

Questions

My file has addresses, not coordinates. Can I map it?
Not with this tool, which plots coordinates only. Geocode the addresses first, then come back with the latitude and longitude columns.
Is my data uploaded?
No. The file is read by JavaScript in your browser. The only network traffic is the map tiles.
Why are some rows skipped?
Their latitude or longitude was blank, not a number, or outside the valid range. The skipped list under the controls names each row by its line number.

All map tools, free and without an account. Location data is processed in your browser and by the open geocoding services named on the sources page; nothing is stored by this site.