Check out this online Unity WebGL demo to test Stats Monitor v1.3.0, which has been submitted to the Asset Store yesterday and should be available shortly, and see how many spheres you can spawn before your framerate drops into the cellar.

Update 1.3.0 provides several new features such as showing you the current count of rendered objects, the fixed update rate, and blips on the graph whenever a garbage collection occurs.

Stats Monitor is available at!/content/44870