Chromecast Ultra is designed to pick the maximum refresh rate (up to 60Hz) and resolution supported by your 4K Ultra HD TV's HDMI connection. Some TVs are incapable of a 60Hz HDMI connection at 4K resolution. When connected to such a TV, the video smoothness feature will select a 1080p 60Hz connection to ensure fluid playback and prevent jerkiness or stuttering issues when viewing content. Video smoothness is on by default.
- Chromecast Ultra will prioritize playing the content at the highest resolution while lowering the frame rate to fit the constraints of the TV. So a 4K TV that doesn't support 4K 60Hz will default to 4K 30Hz.
- Your content may appear jerky or stutter.
- Even if you turn off video smoothness, streaming services may force a higher frame rate to maintain video smoothness. This happens on the partner side and can’t be overridden by Chromecast Ultra.
Turn off video smoothness
- Make sure your mobile device or tablet is connected to the same Wi-Fi or linked to the same account as your Chromecast.
- Open the Google Home app .
- Tap your Chromecast Ultra.
- Tap Settings .
- Scroll to “Display” turn off Video smoothness.
Read more about streaming 4K Ultra HD content with Chromecast Ultra.