480p (60Hz)
But who would want to go lower than 4K 60Hz? If you need to, there are now more options.
Chromecast Connectivity Reliability Improved
These granular controls might not matter if the bugs in Wi-Fi and Bluetooth connectivity persists. Google also fixed these reliability bugs.
In a report by Android Central, you may now say goodbye to the stuttering problems with Bluetooth audio that ruins your binge-watching. If you re on a 5Ghz Wi-Fi or a Mesh network, good news, expect better stability on the new update.
The complete list of improvements on the latest Chromecast update is listed below: