Stream an webradio to an Speaker

Hey,

Has someone an idea how to make an arduino Uno streaming an webradio to an speaker with an Ethernet shield?

I do not think Uno can do that. It does not have enough speed/memory.

Perhaps esp8266 or esp32, or Raspberry Pi.

Is there an shield what i can use?

Not one that is commonly available, I think. You will have to search the web.

The Raspberry Pi Zero W is cheap. It is slow when running a desktop, but if you know linux and can make a webradio with only the command interface, then it is a good choice. You also need a USB-external-soundcard.

Ive got an raspberry pi

Raspberry Pi 3 or 4 can play streaming music no problem, we tested by playing youtube music sites.
There is an amplifier called HiFiBerry miniamp that plugs on the RPi to amplify and drive speakers. Works on Pi4B also.

I mounted a couple of these in a little box, and they sound pretty good.
https://www.digikey.com/en/products/detail/visaton-gmbh-co-kg/BF-32-8-OHM/9842348

(terrible pics! I need a tripod or something for my phone camera)