Currently, you can easily play a big part of the Xbox Game Pass library on your Android phone or tablet thanks to Microsoft's game streaming service Xbox Cloud Gaming (previously known as xCloud). But Microsoft has never made any secrets about the fact that they are trying to get this to work on iPad/iPhone and PC browsers as well.
This way, your old crappy laptop or even a fairly old iPhone can suddenly run a game like Microsoft Flight Simulator or Halo Infinite when it launches for the service later this year. And now The Verge reports that the testing has started for specifically browsers to both iOS and PC, and has a few details of how it works.
The web version of Xbox Cloud Gaming includes a smaller launcher that offers suggestions based on your taste. You do need a controller to play through the browser, but it doesn't necessarily need to be the Xbox brand. The Verge says they don't know which resolution Microsoft currently uses, but adds that the games are running in full screen.
You can check out an image of what the service looks like for PC below, and you'll find both more images and information at the link above.