Noisy is a jQuery plugin that adds random noise to a given element.
Here's an example:
But since all parameters are optional you can just use it like this:
You can try the interactive demo here.
Just download the repository and link to the local minimized script
Or link via cdnjs.com
What's wrong with using an image?
Due to the random nature of background images with a noisy overlay, compression usually isn't very effective. With this 1 KB script you can generate images up to 300 KB without loading for even a second. Saving bandwidth costs and loading time.
Trying out an image with a different noise opacity involves a much smaller amount of steps by just updating a parameter than changing and saving the image in Photoshop.
I'd be flattered if you'd flattr this :)
If you have any questions or suggestions that doesn't fit GitHub, send them to @DanielRapp