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 Juneyao Airlines. They are 63% cheaper than Hong Kong Airlines. (Average prices, based on 215 datapoints.)
At Beijing the most flights depart around 11:00. (Hourly flights, based on 303 datapoints.)
From Beijing it is on average the cheapest to fly to Guangzhou and to Xiamen. (Average prices, based on 102 datapoints.)
From Beijing most of the flights depart to Guangzhou, second best connected from Beijing is Xiamen. (Daily flights, based on 56 datapoints.)
