Keepgo

Keepgo has been operating since around 2011 as a prepaid data provider, earning its reputation through longevity in a competitive market. Rather than selling a standalone China plan, it bundles China into its wider Asia regional package, which appeals to travelers moving across the continent.

A key perk is the carry-forward data balance, which stays active as long as you top up roughly once yearly, letting frequent Asia travelers preserve unused data between trips.