With most smartphones coming in 2020 with a high refresh rate display, it makes sense that Android 11 would bring an option to show that refresh rate on the screen.
It's a new option that you can turn on in the Developer Settings, with the first preview for Android 11. Obviously, this is really only a feature that developers are going to be using, to test out their apps and such, so it makes sense that it is in the Developer Settings portion of the system settings.
The refresh rate appears in the upper left-hand corner of the display
With the option enabled, the refresh rate will appear in the upper left-hand corner of your display. Just below the status bar, it'll actually be an overlay. So it could become annoying for those that like a clean display.
It shows 60 in red, and 90 in green. More than likely, it will also show 120 in green too. But so far, there are no 120Hz devices running Android 11, so it's hard to say just yet.
For those that are curious how often their Pixel 4 is switching from 60Hz to 90Hz, this is going to be a cool way to see it in action. Since Google does say that it is not always at 90Hz, and that's to conserve power and battery. Especially since the Pixel 4 and Pixel 4 XL have tiny batteries inside.
The Galaxy S20 is also going to dynamically change from 120Hz to 60Hz too, so once those phones get Android 11 – likely early next year or late this year – you could watch it there too.
It looks a lot like Fraps
Google likes to have fun with things and it looks like it is doing that again with this new option.
As the refresh rate looks a lot like Fraps. Which is a PC software that you can use to capture content in games and also display the current frame rate. This was likely done on purpose as a really easy easter egg from Google. Hopefully Fraps won't be too upset and force Google to change it. However, since this is a Developer Option, the likely hood of a lot of people using this feature is very small. It'll likely only be used by a handful of developers and maybe some curious users.
But nonetheless, a pretty fun touch by Google.
It's possible that Google removes this feature when the stable release does come out later this year. As that does tend to happen with some features, so we'll have to wait and see.