Can you use a Google Chromecast without internet?

You may think you need an internet connection to use Google's Chromecast function. In fact, the partly-discontinued technology relies on local connectivity.
Business Insider

How to use your Chromecast without a Wi-Fi connection, and cast all of your favorite content even without internet

You can use your Chromecast device without Wi-Fi, and still cast all of your favorite content to your TV from another device. If you can't connect to Wi-Fi, you can still stream to your Chromecast by ...
The Droid Guy

How to fix Galaxy S9 wifi issue: wifi won’t allow internet connection, can’t cast to Chromecast

I have a new Samsung Galaxy S9. I am trying to connect to my home wifi. it shows as trying to connect, but it never connects. other devices including my previous phone, laptop and chromecast all ...