A data processing method and apparatus, and an electronic device, a system and a storage medium are provided. The method is applicable to a main thread in a Web client and includes: obtaining audio and video data of a target video from a server decapsulating the obtained audio and video data to obtain first audio and video data; sending the first audio and video data to a target sub-thread in the Web client, so that the target sub-thread decodes the first audio and video data to obtain second audio and video data and sends the second audio and video data to the main thread; receiving the second audio and video data sent by the target sub-thread; and rendering video data in the second audio and video data by using a rendering module of a browser of the Web client, and taking the rendered video data and audio data in the second audio and video data as to-be-played data for the target video. The technical solution according to the embodiment of the present application allows a Web client to play audio and video data without browser plug-ins.