You can use your Chromecast device without Wi-Fi, and still cast all of your favorite content to your TV from another device.
Do I need Internet if I have unlimited data?
While unlimited data plans make the technology less necessary for phones, many home devices, from a MacBook to an Amazon Echo, still use Wi-Fi to connect to the internet. Wi-Fi also helps fill in gaps in some office buildings and homes that have spotty cellphone coverage.
Can you connect phone to TV without WiFi?
Screen Mirroring Without Wi-Fi Therefore, no Wi-Fi or internet connection is required to mirror your phone screen onto your smart TV. (Miracast only supports Android, not Apple devices.) Generally, however, with a Wi-Fi connection you can successfully screen mirror your device and have a better experience.