Graphene has been hailed as a revolutionary membrane material because of its many alluring features and the ease in their tunability. In specific to gas separation industry, the exceptional molecular transport, the possibility of fabricating membranes having thickness at a nanoscale range and the robust lattice structure that can withstand to the rigorous perforation methods render graphene to stand ahead of its contemporary materials. Moreover, its broad chemical tolerance and high mechanical strength facilitate the mass-production of membranes possessing macroscopic dimensions and their subsequent long-term operation under harsh environments. In this concise review, we complied and discussed the progress of gas-separation performance of graphene-based membranes with a prime focus on recent advancements in scalability, functionalization/modification along with the new manufacturing processes including the budding approaches through synthetic chemistry. The strategies implemented, the factors that influenced the membranes’ performance and the corresponding transport mechanisms were highlighted in detail. In the end, we outlined the daunting challenges facing by these graphene-based membranes in realization of their prospects as well as the proposed measures for alleviating them.