Heat map generator

From spreadsheet to shaded map

The input is a two-column list: a region name and a number. Population, revenue, price, turnout, response rate, headcount - anything numeric per region works. Paste it in and each region is matched by name and shaded on a continuous scale.

Rows that do not match a region are reported rather than dropped, so a misspelling is something you fix in a second instead of a gap you notice after publishing.

Gradient or banded, whichever suits the data

Continuous shading and hard cutoffs answer different questions, so both are available.

Choosing colors that are actually readable

A single-hue ramp - light to dark in one color - is the safest choice for data that runs from low to high, because the reading order is obvious even in greyscale. Reserve two-color diverging scales for data with a real midpoint, such as change versus a baseline or a margin between two options.

Avoid rainbow ramps. They imply boundaries that are not in the data, and readers cannot tell which end is high without checking the legend every time.

Where the detail is

Country-level maps are fine for international comparisons, but most heat maps get more useful the further down you go. US counties, Indian districts and UK counties all reveal variation that disappears entirely at the national level.

Popular maps for heat maps

Every map below opens blank and ready to color. Browse the full library →

Frequently asked questions