The 5.5-inch display used by HTC features an HD resolution – so 1280×720. Stretched across the large display, it means the Desire 820 has a pixel density of 267 PPI. This is not as high as we would like, though it's not awful.
Taken on its own, the sharpness of the display is good enough. However, when we consider the LG G3 has a QHD display and can now be bought for the same price as the Desire 820, it does pale in comparison.
A major downfall of the display is the range of back light brightness. The screen is simply not bright enough for most use outdoors, and can cause your eyes to really strain to see the display. We find it very frustrating when manufacturers do not allow for use in sunlight, as it lessens the overall experience of using a smartphone.
Viewing angles are good, though, and give a clear picture at wide angles. This means watching a film lying down, for instance, does not present a problem.
It is a large screen – which we like due to the increased productivity a larger display can bring – but it does fall short in the key areas of screen resolution and brightness.