By Team Edtoolkits · Charts
Compare numeric columns across categories in a labeled color matrix.
Use the guide alongside the working tool.
Open Heatmap Maker →A small dataset to try
Team,Planning,Delivery,Support
Alpha,8,6,9
Beta,5,9,7
Gamma,7,8,5If these are ratings on the same 0–10 scale, Alpha stands out in Support and Beta in Delivery. That interpretation depends on all three columns using the same rating method.
When to choose this chart
A heatmap uses colour to compare a numeric matrix across categories and measures. It is useful for scanning patterns when reading every cell as a separate bar would be cumbersome.
Prepare and map your fields
Choose category labels and numeric columns. Keep measures comparable, or normalize them deliberately before import. Raw revenue and a percentage should not share an unexplained colour scale.
Check rows, column headings and missing-value counts before choosing the palette.
Make the low-to-high colour direction clear and inspect numeric cell labels where available.
Review the matrix in the exported size; small differences can disappear when cells or labels become too tiny.
Read the result correctly
Use colour to locate candidate patterns, then read the values before making a precise claim. A strong colour difference is a feature of the chosen scale as well as the data.
A mistake to avoid
A heatmap does not automatically calculate statistical relationships or standardize units. Choose a correlation matrix when the question is how numeric variables co-vary.
Export and keep your data private
Review the title, units, labels and any omitted-row warnings at the final export size. PNG is a raster image, SVG retains vector chart elements, and PDF embeds a raster image. Save the original table if you may need to revise the mapping.
Data stays in browser memory; no upload, external chart service or AI model. CSV, TSV, semicolon/pipe text, JSON and JSON Lines: 2 MB, 10,000 rows, 24 columns. Charts allow up to eight series; categorical charts 60 groups, lines/scatter/candlesticks 500 rows, pie/donut/waffle 12 categories, radar 3–12 dimensions. Blank/invalid mapped values are omitted and counted. Numeric values use a decimal point; remove currency symbols and grouping separators. Percent strings are treated as displayed numeric values (25% becomes 25). Dates use ISO format. Recommendations check data structure, not meaning or causation. PNG up to 16 MP; SVG stays vector; PDF embeds a high-resolution chart image. Review mappings, ordering, aggregation and labels before sharing.
Ready to apply this workflow?
Try Heatmap Maker →Explore a related workflow
- Correlation Matrix Maker: Examples & Data Guide
Calculate pairwise Pearson correlations with sample counts.
- Chart Studio: Examples & Data Guide
Find suitable charts for your data and create a downloadable chart collection.
- Column Chart Maker: Examples & Data Guide
Compare categories with grouped columns and a clear zero baseline.
- Bar Chart Maker: Examples & Data Guide
Compare ranked categories with horizontal bars and readable labels.
Keep your original files and review the result. Found unclear instructions? Contact Team Edtoolkits.