Venn diagram generator
Name your sets, type the count for each region, and get a clean two- or three-circle Venn diagram with the share of the total worked out for you. It is drawn as plain SVG on your device and exports as SVG or PNG.
Why this one is not a Mermaid page: the engine behind every other tool on this site cannot
draw a Venn diagram. Tested on 6 September 2026, mermaid 11.17.2 — the current latest release on jsDelivr — answers a
venn block with “No diagram type detected matching given configuration”, while pie
and radar-beta parse in the same build. So this page draws its own SVG.
Sets and counts
Fill in regions, not sets
The mistake that breaks most hand-drawn Venn diagrams is entering set totals where region counts belong. A Venn diagram’s regions are disjoint: “A only” means in A and in nothing else. Enter it that way and the numbers add up to the total, every share is meaningful, and each set size can be recovered by adding the regions its circle covers — which is what the panel under the inputs prints for you.
Working the other way round is easy too. If you know that 42 people read the docs and 22 of them also run the tests, then “A only” is 42 − 22 = 20. With three sets, subtract the centre first: A only = |A| − (A∩B) − (A∩C) + (A∩B∩C), because the people in all three were removed twice.
Schematic Venn, not area-proportional
The circles here are equal and fixed. That is deliberate: an area-proportional diagram — an Euler diagram — can only be drawn with true circles for some combinations of counts, and forcing one for the rest produces a picture that is quietly wrong. A schematic Venn with the counts printed in each region says exactly as much, and says it accurately, which is why it is the form used in textbooks and slide decks.
Three circles is also the practical ceiling for circles: four sets cannot be drawn with four circles showing all fifteen regions, which is why four-set Venn diagrams use ellipses instead. If you need more than three sets, an UpSet plot or a plain table of intersection counts will communicate better than any shape will.
Where this fits with the rest of the site
Everything else here is Mermaid-based, and Mermaid is excellent at graphs — things with nodes and edges. A Venn diagram is not a graph, it is a picture of set membership, so it needs different code and got it. For the graph shapes, use the flowchart generator, the mind map generator or the tree diagram generator; for probabilities over branching outcomes, the probability tree generator is the closer fit. The Mermaid editor lists what the engine does cover, and the examples library has one of each.
Mermaid capability checked on 6 September 2026 by importing mermaid@11.17.2 from cdn.jsdelivr.net in a browser and
calling parse() on a venn block, a pie block and a radar-beta block;
11.17.2 was the version behind the package’s latest tag that day. Mermaid ships often — read this
as a dated measurement, not a permanent limitation.
Frequently asked questions
Can Mermaid draw a Venn diagram?
Not in the version shipping today. Tested on 6 September 2026, mermaid 11.17.2 — the current latest release on jsDelivr — rejects a "venn" block with "No diagram type detected matching given configuration", while pie and radar-beta parse in the same build. That is why this page draws its Venn with its own SVG code instead of the Mermaid engine the rest of the site uses.
How do I make a Venn diagram with three sets?
Switch to three sets, name them, and fill in the seven region counts: the three "only" regions, the three pairwise overlaps and the centre where all three meet. The diagram redraws as you type and the shares are recalculated from the totals you entered.
What do the numbers in each region mean?
Each number is the count of items in that region and nothing else — "A only" excludes anything that is also in B. That is what makes the arithmetic work: the regions are disjoint, so they sum to the total. The tool shows each region as a percentage of that total.
How do I get the size of a whole set?
Add up every region the circle covers. For two sets, |A| = A only + the overlap. For three, |A| = A only + (A∩B) + (A∩C) + (A∩B∩C). The tool prints these set totals under the diagram so you can check them against your source data.
Are the circle areas proportional to the counts?
No. This draws a schematic Venn diagram with fixed, equal circles — the standard classroom and slide-deck form. Area-proportional diagrams (Euler diagrams) cannot represent every combination of counts with real circles, so a schematic Venn is the honest choice when the point is which regions exist and how big each one is.
Is it free, and is my data uploaded?
Free, with no signup and no watermark. The diagram is drawn in your browser as plain SVG, so your labels and counts stay on your device — nothing is sent anywhere.