I'm looking to generate noise that looks like this:

(images courtesy of Understanding Perlin Noise)

I'm basically looking for noise with lots of small "ripples". The following is undesirable:

Are there any simple ways to do this? I've been looking at perlin and simplex for a week now and I can't seem to ever get it to work in JavaScript, or when I do, I don't have the correct parameters to generate such images, or it is excruciatingly slow.

I understand that the 3 images I posted could probably be achieved by the same algorithm but at a different scale, but I don't need that algorithm. I just need a very simple algorithm to achieve something like in the first image ideally. Maybe some kind of blurring would do the job, but I can't manage to have results.

I'm developing this in JavaScript but any kind of code or even a simple and detailed explanation will work.