MapSplit

Data: —

Basemap

Natural Earth 1:10m (public domain), simplified and inlined as an SVG path — no map tiles.

MapSplit: draw a movable straight line across the UK and reports a statistic for each side.

Using it

• Select a dataset from the drop down or upload your own file (see below how to). Where its numbers came from is listed under Sources, linked below the drop down.
• Drag the line across the country; rotate the handle to any angle.
• Use ↔ Horizontal and ↕ Vertical to snap back to a level line.
• Check the totals and the partial breakdown in What's being counted. When a line runs roughly north–south the split is labelled West/East instead of North/South.
• Hover a point to see more a data tooltip.

Loading your own data

Drag a file onto the map, or use the upload button. A dialog lets you confirm which column is which. Accepted files: CSV/TSV, GeoJSON points or polygons, and JSON or ESRI-ASCII grids. The minimum each needs:

• CSV/TSV: a column for longitude, one for latitude column, and a numeric value column. An optional text column can group the points.
• GeoJSON: Point/MultiPoint, or polygons (reduced to their centroids), with a numeric property.
• Grids: a bounding box (or origin + cell size) and a numeric value per cell.

IMPORTANT: coordinates must be unprojected WGS84 longitude/latitude in degrees (EPSG:4326).

Play the daily game

MapSplit Play turns this into a daily puzzle: three statistics a day, and you find the line that splits each one in half.

Development notes

This website was developed by Giuseppe Sollazzo with an LLM-aided workflow using Claude Opus 5 and manual tests.

The datasets were created by cleaning and merging the source data above using a manually created Jupyter notebook