Most of the world's Accelerator Laboratory provides stable beam services through numerous control devices. In addition, EPICS (Experimental Physics and Industrial Control System) software is used to acquire the normal status and data of the device through a LAN (Local Area Network). The software that plays a central role in EPICS is an Input / Output Controller (IOC) and communicates directly with the device. EPICS provides a number of tools for controlling or monitoring control devices using the Operator Interface (OPI). However, most OPIs only provide an environment that works on a PC. Therefore, when a problem occurs due to failure of a main device during operation of the beam, the person in charge of the device cannot quickly check the status of the device with the smartphone. To improve this inconvenience, we will apply the user - oriented OPI according to the redevelopment of the superconducting LLRF System at KAERI. In this paper, we propose a method to remotely control and monitor real-time device information from a smartphone as well as a PC. By observing the Web standards, we confirmed that remote devices can be controlled and monitored in various web browsers. We introduce web-based OPI using HTML5, Web Socket, and communication between IOC and web server.