An electronic device and an operating method thereof. The electronic device includes a receiver for connection to a source device, a memory storing one or more instructions, and a processor configured to execute the one or more instructions stored in the memory to detect a first resolution of an input image received from the source device, determine whether to modify extended display identification data (EDID) of the electronic device, based on whether the detected first resolution corresponds to the EDID, upon determining that the EDID is to be modified, modify the EDID, and receive, from the source device, an input image of a second resolution, generated based on the modified EDID.