Do smartphone manufacturers often cheat in their advertising of display brightness?

Xiaomi advertises a top brightness of 1500 nits for the HDR10+ certified AMOLED panel of the 12S Pro. The same also goes for the flagship smartphone from the Chinese manufacturer, the Xiaomi 12S Ultra. However, our display measurements don't confirm these values. In the realistic APL18 test, we measure a maximum brightness of 952 cd/m² for the Xiaomi 12S Pro, and a very similar 983 cd/m² for the Xiaomi 12S Ultra. Our two test units don't even come close to their advertised 1500 nits in our measurements.

However, Xiaomi isn't alone in this, and other manufacturers show the same problem – for example OnePlus or Oppo. In terms of display brightness, the AMOLED panel of the OnePlus 10T only reaches a maximum brightness of 873 cd/m² in our APL18 measurements, and the top OnePlus 10 Pro model only reaches 799 cd/m² but measured with the APL50. While the APL18 still leaves some room on top, the advertised 1300 nits aren't reached here either. The same goes for the Oppo Find X5 Pro. At 816 cd/m², the OLED display is as bright as the OnePlus sibling models, but we are still unable to tickle the advertised 1300 cd/m² from the smartphone, not even close.

Possibly the displays of these smartphones might reach the advertised brightness of far above 1000 cd/m² in some specific scenarios, but in everyday usage, this is hardly relevant. That things can be done differently is shown by Samsung. At 1,788 cd/m² in our APL18 test, the Galaxy S22 Ultra reaches almost exactly the advertised manufacturer specifications of 1,800 nits. And Honor also comes much closer to its spec sheet (1,000 nits) with the 956 cd/m² we measure for the Magic4 Pro, even if this brightness is at a much lower level than that from the Korean manufacturer.  

If you value a powerful upper-class smartphone and are not afraid of importing one, you can get a detailed impression of the Xiaomi 12S Pro in our extensive test of the Xiaomi smartphone.