1. display: mi band 9 adopts 1.56-inch AMOLED display, and 8 Pro adopts 1.39-inch AMOLED display. The display screen of the bracelet 9 is larger.
2. battery life: mi band 9 has a relatively long battery life and can be used for a longer time.
3. Sensors: mi band 9 has more health monitoring sensors, such as oxygen saturation, sleep breathing quality detection and other functions, while 8 Pro does not have these functions.
4. Sports modes: mi band 9 supports 19 sports modes, while 8 Pro only supports 7 sports modes.
5. Charging method: mi band 9 adopts magnetic charging method, and 8 Pro adopts plug-in charging method.
Please note that these are only some major differences, and there will be subtle differences in other aspects. The specific choice of bracelet needs to be decided according to personal needs.