A free Venn diagram maker that needs no installation and runs entirely in your browser. Type a heading and the items for each of the two sets, and they are laid out inside the ellipses right away. Overlap, radii, colours, and text sizes are all set from the panels, and the finished diagram saves straight to PNG. Ready to use for classroom handouts and slides.
In the Data panel you set the number of lines and the text of each line for the left set, the right set, and the overlap; the heading sits above its ellipse. The Shape panel changes the overlap, the radii, the fill, the outline, and where the text sits, and the Text panel changes size, colour, and line height. Lines break only where you add one.
The drawing area is a canvas: zoom with the wheel and drag to move it. The thin frame shows what gets saved, and Save as PNG writes exactly that area at the size you set. Double-click a panel title to switch how the panels are laid out: in the movable layout you drag them wherever you like and keep several open at once, and in the fixed layout a single panel sits in the top right.