Data & CSV

CSV heatmap builder

Explore a numeric matrix as a labelled heatmap, with readable values and SVG export.

CSV heatmap builder
Esc to restore

Make it yours

Inputs and settings

UTF-8 CSV with the example headings. Files stay on your device.

Up to 25 MB per file, 50,000 data rows, 200 columns and 2 million data cells. Fully blank rows and columns are ignored before row, column and cell limits are checked. Individual tools may have smaller result or chart limits.

Adjust the inputs, then update the preview. Sliders and selectors update directly.

Files stay on your device

See it take shape

LOCAL & PRIVATE

Preparing your workspace…

Your files and work stay in this page. Export anything you want to keep.

A clear answer. Here’s how.

First column contains unique row labels; remaining columns contain finite plain decimal numbers or blanks. Supports 1–40 rows, 1–30 numeric columns, labels up to 120 characters and values within ±1 trillion. Sequential colours span the observed minimum and maximum; an all-equal matrix uses the midpoint. Diverging colours use equal absolute magnitudes around zero. Blank cells are grey and marked with a dash. Every cell includes its value, and an accessible table and original-value CSV accompany the SVG. Colours are a visual aid and do not change or normalise the values.

Keep going.

CSV dataset diffCSV rule validatorCSV calculated columnCSV rank and percentile