Right now, Spotify works with Chromecast and Chromecast Audio. We continue working together with Google to bring the experience to more Cast enabled devices as soon as possible.
If you have Guest Mode enabled on your Chromecast, nearby devices can connect to it without having to join your WiFi network. So it’s great for when you’ve got friends over. See the Guest Mode FAQs for more information.
If you’re having trouble with Spotify and your Chromecast, please check the following: