The difference between outdoor LED display P4 and P8 is different in different aspects, the following is the main difference between outdoor large screen P4 and P8:

Pixel pitch
The pixel pitch of P4 display is 4mm, which means that in the unit area, the pixels are denser, which can present a more detailed image and higher clarity.
The pixel pitch of P8 is 8mm, which means that the pixels are relatively sparse, and the degree of detail and clarity of the image will be lower than that of P4.

Resolution
Due to the small pixel pitch of P4, so in the same size screen, P4 display resolution is higher. For example, an area of 10 square meters of outdoor screen, P4 display can show more details and clearer text, images.
The resolution of P8 display is relatively low, and may not be able to meet the demand for some scenes with high resolution requirements. But in some long-distance viewing occasions, P8 resolution can also basically meet the requirements.

Visual distance
P4 display is suitable for close viewing. Generally speaking, in the range of 4 meters to 20 meters distance, can get a better visual effect. Within this distance, the details and colors of the image can be clearly seen.
The viewing distance of P8 display is relatively far. It is usually better viewed at a distance of 8 meters to 50 meters or even more. This is because the pixel pitch is larger, and you will not feel the obvious graininess when viewing from a distance.

Brightness
In general, the brightness of P4 and P8 outdoor display can meet the needs of the outdoor environment. However, because the P4 pixels are more dense, heat dissipation is relatively difficult, and may require higher technology and cost to ensure heat dissipation under the same brightness requirements.
P8 display due to the pixel pitch is larger, heat dissipation is relatively easy, in the realization of the same brightness may be relatively easy.

Price
P4 display due to higher technical difficulties, dense pixel points, production costs are relatively high. Therefore, its price is usually more expensive than the P8 display.
P8 display is relatively more affordable, for some projects with limited budget, it is a more economical choice.

Therefore, the choice of P4 or P8, mainly depends on the specific use of the occasion and viewing distance and other needs. If you have any related questions, welcome to contact Apexls.