Please be aware that Beijing has multiple airports and that these results are only for Daxing International Airport.
The cheapest airline flying to Beijing is Capital Airlines. They are 50% cheaper than AirAsia X. (Average prices, based on 235 datapoints.)
At Beijing the most flights depart around 09:00. (Hourly flights, based on 362 datapoints.)
From Beijing most of the flights depart to Shanghai, second best connected from Beijing is Hong Kong. (Daily flights, based on 89 datapoints.)
