Heatmap CSV Data Visualizer
Create a heatmap from CSV data online. Visualize patterns across two categorical dimensions with color intensity. Upload your CSV and export as PNG.
CSV to Heatmap — Free Online Tool
A heatmap encodes a numeric value as color intensity across a two-dimensional grid of categories. It is ideal for spotting patterns in matrices — feature correlation tables, time × day activity grids, cohort analysis results.
Select an X column and a Y column (both categorical), and the tool counts occurrences at each (X, Y) intersection and encodes the count as a color. Upload a CSV with at least two categorical columns to get started.
Frequently asked questions
Can I use a custom numeric value instead of counts?
Currently the heatmap uses row count per cell. Support for a custom Z-value column is on the roadmap.
Next step
Charting a CSV export means the data already went stale.
Every refresh is another export, another upload, another chart. Connect the source itself to your AI agent with Sequel and ask for the chart against live data.
Ask your agent
“Chart weekly signups for the last quarter and call out the inflection points.”