Venn diagram encodes values as intersection area of overlapping closed curves. John Venn, 1880; Euler drew related region diagrams earlier.
In reports, ads and assignments it fits two or three sets with a real overlap story. Skip it when four-plus sets, or when sizes must be to scale.
Software
- Software 1 — Excel or Google Sheets
- Software 2 — PowerPoint
- Software 3 — Figma / Illustrator — ad and poster shapes
- Software 4 — Python matplotlib or R ggplot — assignment and research figures
- Software 5 — This atlas’s server-rendered SVG — examples without a chart library
Exports
- Exports 1 — SVG
- Exports 2 — PDF
- Exports 3 — EMF/SVG into slides (no screenshots)
- Exports 4 — SVG for web, PDF for print
Accessibility
- Accessibility 1 — Never hue alone. Stack pattern, label and position.
- Accessibility 2 — 4.5:1 for text, 3:1 for large marks.
- Accessibility 3 — Short alt text on the chart; numbers also as an HTML table.
- Accessibility 4 — Motion only as emphasis. Honour prefers-reduced-motion.
Venn diagram: honour intersection area of overlapping closed curves, and switch when four-plus sets, or when sizes must be to scale.