Nits is a measure of brightness, or more accurately, of luminosity. Your screen, whether it’s an internal one or an external one, outputs a certain number of nits and this measurement is a part of its basic specifications. The nits value of a monitor is usually mentioned on its box, or on the manufacturer’s website. You can use dedicated hardware to measure it as well. To measure nits value using just a software solution you can use an app called DisplayHDR Text.
It goes without saying that this app will give you an approximate nits value. If you want an absolutely accurate value, you’re going to have to use either photometer or you can search for the information about your screen online.
Measure nits value
Download DisplayHDR Text from the Microsoft Store. This app runs a series of tests to check if your screen can display HDR content or not. To do so, it will run a nits test at 400, 600, and 1000 nits. It does this regardless if your screen can support it or not.
You do not need to run any of the tests. All you need to do is tap the Page Down key twice when you see the following screen.
You will see the following summary. The Max peak luminance gives you the nits value for your screen. This isn’t going to be accurate but the difference won’t be more than 50 nits. The screen I tested this app on outputs 250 nits per the manufacturer so the difference isn’t more than 20 nits in my case.
If you want, you can run one of the luminance tests and that too will display the nits value that your screen supports though it may also run them for lower nit values. Run the tests to see the maximum value that the app runs the luminance test for.
This information is needed if you want to check whether or not your screen can output HDR content on Windows 10. Of course, it’s not the only requirement for displaying HDR but it’s the larger component. If your screen has low nits, you won’t be able to increase it with software. You will have to buy a new monitor that can support HDR.
For a multi-screen set-up, move the app to the screen that you want to test. Better yet, set the screen as your primary screen and launch the app directly on that screen. Make sure you enable HDR in the settings app when prompted to before starting any of the tests.