usefulweb.site Geo Data Visualizer

Charts & data

Geo Data Visualizer

Map CSV coordinates or GeoJSON as points, proportional circles, hex-bin heatmaps or choropleths.

Max 20 MB. CSV/XLSX: lat/lon columns or a country column (ISO code or English name). GeoJSON: Point, LineString, Polygon (and Multi-) geometries.

CSV with a header row, or GeoJSON.

Empty: a column named lat/latitude.

Empty: a column named lon/lng/longitude.

Numbers for circle size, hex sums or choropleth shading. Empty: the first numeric column (or a "value" property in GeoJSON).

ISO 3166 alpha-2/alpha-3 codes or English country names.

px

Try an example: Offices as proportional circles (staff, example data) · Choropleth by ISO code or country name · GeoJSON points, a route and an area (Mercator) · Hex-bin density of the same offices

How it works

Upload a CSV/XLSX with latitude/longitude (plus optional value and label) or a country-code column, or a GeoJSON file with points, lines and polygons. Get an SVG map over bundled Natural Earth country outlines in the Equal Earth, Mercator or equirectangular projection – as points, proportional symbols, a hexagonal-bin heatmap or a choropleth – zoomed to your data, with SVG/PNG downloads.

  • Input detection: text starting with "{" is read as GeoJSON (FeatureCollection, Feature or bare geometry; Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, GeometryCollection). Anything else is a table (CSV/TSV/XLSX); lat/lon and country columns are found by name unless you name them.
  • Coordinates must be WGS 84 decimal degrees (longitude −180…180, latitude −90…90); rows outside the range or without numbers are skipped and counted.
  • Projections: equirectangular x = λ, y = φ; Mercator y = ln tan(π/4 + φ/2) (clipped at ±85°); Equal Earth (Šavrič, Patterson & Jenny 2018), an equal-area projection suitable for world maps and for comparing densities.
  • Auto zoom fits the bounding box of the data plus 20 % margin (at least 4° × 3°); views wider than 300° of longitude show the whole world.
  • Hex-bin heatmap: points are projected, assigned to pointy-top hexagons of the chosen pixel size (cube-coordinate rounding) and coloured by count, or by the sum of the value column, on a colour-blind-safe viridis-like ramp.
  • Proportional circles: circle area is proportional to |value| (radius ∝ √value, largest 26 px); larger circles are drawn first so small ones stay visible. Choropleth: country codes/names are matched to the bundled outlines and shaded in up to five quantile classes; unmatched entries are listed.
  • Country outlines are Natural Earth 1:110m (public domain): small countries and islands such as Singapore, Malta or Andorra are not part of this scale and cannot be shaded. Borders follow Natural Earth’s de facto conventions and are not a statement on disputed territories.

Sources

For scripts and AI agents

  • JSON API: POST https://geodatavisualizer.usefulweb.site/api/v1/calculate (same calculation as this page)
  • Interface description: OpenAPI 3.1 · AI guide: llms.txt
  • MCP server (Streamable HTTP): https://geodatavisualizer.usefulweb.site/mcp · tool name geo_data_visualizer
Example request
curl -s -X POST https://geodatavisualizer.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"data":"office,lat,lon,staff\nTokyo,35.68,139.69,42\nDelhi,28.61,77.21,18\nShanghai,31.23,121.47,25\nSão Paulo,-23.55,-46.63,12\nMexico City,19.43,-99.13,9\nCairo,30.04,31.24,6\nMumbai,19.08,72.88,21\nNairobi,-1.29,36.82,7\nNew York,40.71,-74.01,55\nLagos,6.52,3.38,8\nParis,48.86,2.35,31\nLondon,51.51,-0.13,47\nBerlin,52.52,13.40,26\nToronto,43.65,-79.38,14\nSydney,-33.87,151.21,11","mode":"proportional","valueColumn":"staff","labelColumn":"office","zoom":"world","title":"Staff per office (example data)"}'

Related tools

  • CSV/Excel Chart Studio – Turn CSV, TSV or Excel data into line, bar, pie, scatter or histogram charts with SVG/PNG export.
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