counting visible divs with class name jquery

Pretty sure you need to do $(".level1:visible").length;

the Space is breaking the code

$(".level1 :visible") is a descendant selector: you are selecting all visible elements that are descendants of .level1. There are three div elements that are visible beneath .level1 elements.

Use this instead:

$(".level1:visible").length;

See your fiddle per my update.