Heatmap Generator
Turn a numeric matrix into a colour-coded heatmap with a continuous ramp, clipping control, row and column labels, per-cell values and a ticked colour-scale legend.
A first row whose cells are not all numbers is treated as a column header. The first column of each row is used as the row label when a header row is present. Limits: 80 × 80.
Colour scale
Scale & clipping
Active domain: 18.0 → 72.0
Cells & labels
Export
Live preview
5 rows × 6 columns · 30 values
Hover any cell for its exact value; the hovered cell gets an outline.
About this tool
The Heatmap Generator maps a numeric matrix onto a continuous colour ramp — Viridis, Magma, Blues, a diverging red to green, or your own two colours — with optional percentile clipping and manual min/max overrides so outliers do not flatten the scale. Cell values, row and column labels and a ticked colour-scale legend are drawn into the same inline SVG you download. Rendering and hover inspection are entirely local to your browser, and the matrix is capped at 80 × 80 so the preview stays responsive.
- 100% free — no account needed
- Runs in your browser
- Nothing is uploaded
Frequently asked questions
Is Heatmap Generator really free?
Yes. Heatmap Generator is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.
Does Heatmap Generator upload my data?
No. Heatmap Generator runs entirely inside your browser, so anything you type, paste, or open stays on your own device.
Do I need to sign up or install anything?
Neither. There is no account and nothing to download — open the page and Heatmap Generator is ready to use on desktop or mobile.
Does Heatmap Generator work offline?
Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.
More design & visual
CSS Gradient Generator
Create linear CSS gradients with a live preview.
CSS Box Shadow Generator
Build and preview CSS box-shadow values with one-click copy.
CSS Glassmorphism Generator
Generate frosted-glass CSS with backdrop blur and copy-ready styles.
QR Code Generator
Generate custom QR codes for any text or URL.
WiFi QR Code Generator
Generate a scannable QR code to share WiFi credentials instantly.
Letter Profile Picture
Generate avatar images from initials with custom colors.