This article will show you how to adjust the resolution of your Chromecast when casting content to your TV.
How to Change TV Resolution on Chromecast with Google TV (Quick Method)
Google Chromecast is a unique casting device: when you stream content to your TV using a Chromecast, the Chromecast device itself connects directly to the internet to get that stream. Even if you start the video on your phone or tablet and send it (i.e. cast) to the Chromecast, the Chromecast does not rely on your smart device to send the stream to the Chromecast.
Because of this, you can't directly adjust the Chromecast resolution using the Google Home app on your mobile device. Instead, Chromecast will automatically adjust the aspect ratio depending on the resolution of the connected TV.
This means that the easiest way to ensure that the Chromecast is streaming in the correct aspect ratio is to set your TV to the highest resolution that you want to use. If you do this before casting to the Chromecast device, it should automatically adjust the aspect ratio of the stream to the correct resolution.
