Name each set and list its items, one per line. The tool finds which items are in one set, two or all three, and writes them in the right part of the diagram. Nothing is uploaded.
One item per line. Items match without regard to case, so “Cat” and “cat” are the same. Each region lists up to five (two sets) or three (three sets) items and a +count for the rest.
Each distinct item gets a mask showing which sets contain it, then goes to the region with that mask: A only, B only, A and B and, with three sets, the other four combinations.
Dogs: Labrador, Poodle, Beagle, Husky. Cats: Siamese, Persian, Husky, Beagle. Husky and Beagle are in both lists, so they sit in the overlap of the first two circles.
An item written in more than one set (ignoring upper and lower case) is placed in the overlap of those sets. Everything else stays in the part of its own set.
The diagram shows the first few and “+n” for the rest, so the picture stays readable.
No. Two and three sets cover the common circle layouts. Four needs other shapes.
Regions are filled from your lists. To label an overlap by hand, put the same text in both sets.