Is Heatmap Builder free to use?

Yes. Heatmap Builder is completely free with no account, sign-up, or subscription required.

Does Heatmap Builder store or upload my data?

No. All processing runs locally in your browser. Nothing is sent to any server, so your data stays private.

Yes. Once the page has loaded, Heatmap Builder works without an internet connection.

Heatmap Builder works in all modern browsers including Chrome, Firefox, Safari, and Edge on desktop and mobile.

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Visualise matrix data as colour-coded heatmaps. Choose from 5 colour scales and export as PNG or PDF.

Grid Configuration

Chart Title

Rows

Columns (Days of Week)

Row Labels (one per line)

Column Labels (one per line)

Display Options

Color Scale

Hot

Cool

Green

Plasma

Greyscale

Show values in cells

Cell Size

Small Medium Large

Data Input

Edit values directly — heatmap updates instantly

Heatmap Preview

Website Traffic Heatmap

Min: 0 Max: 100

How to use

Set the number of rows and columns, plus their labels (one per line).
Click Generate Grid and fill the cells with values — or paste a range from Excel/Sheets.
Pick a colour scale and export the heatmap as PNG or PDF.

FAQ

Hot, Cool, Green, Plasma and Greyscale. The scale automatically maps your dataset's min/max to the two ends of the gradient.

Yes — copy any cell range from Excel or Sheets and paste into the grid. Tab-separated rows are detected automatically.

Nowhere. The heatmap is rendered on a canvas in your browser and nothing is uploaded.