Up until now, the only way you could play on Google Stadia in 4K was on your TV and using a Chromecast Ultra.
They found the option with a green 4K icon under “data usage” in the in-game menu.
If you have Stadia, you can open the in-game menu with shift-tab or using the Stadia Button, then find the icon there.
Google notes that you need to have a Stadia Pro subscription and at least a 35Mbps connection.
However, 9to5Google tested it and said they could get 4K gaming with “good” and “OK” internet speeds, so perhaps you can too.
“Given that the full launch of Stadia Captures on the web followed a similar pattern, an official announcement by Google could come as early as Thursday morning,” said the outlet.
The only drawback is that blockbuster titles like Red Dead Redemption 2 and Destiny 2 don’t support that resolution.
There also isn’t an option to sort games by 4K support, so you’ll have to find them yourself.