Real-time Collaborative Editors (RCEs) are popular distributed applications that permit large and dynamic groups of collaborators to share and update large multimedia documents across many sites in real time. However, the state-of-the-art models are either locally centralized or globally distributed using a central cloud server to keep shared data synchronized. Multi-access Edge Computing (MEC) is an emergent architecture designed to bring storage, control and communication capabilities near to end devices, thus allowing real-time and resource extensive applications to be easily executed on low-capability handheld devices. This paper presents EdgeDoc, an edge-based RCE. Mobiles that are managed by the same edge node are cloned in the edge to offload resource-intensive tasks, whereas only lightweight edition components are handled locally. This provides a more effective solution to manage concurrency and collaboration on mobile devices. To evaluate the performance of the proposed system, a series of experiments were conducted, which show that EdgeDoc reduces latency by around 96%, thereby improving the responsiveness of RCE.