I use it all the time, my favourite is the white rain: https://mynoise.net/NoiseMachines/whiteRainNoiseGenerator.ph...

You can configure it and even calibrate it to your headphones.

I contributed $, which gets me access to the "make your own" feature where you can combine their collection of stems any way you like. Now I have the problem where I can easily spend an hour playing with MyNoise to make the best mix for the work I should be doing.