The local dialect that prevails in Shanghai is the modern Wu – today's southern Jiangsu province – dialect of the Taihu Lake area, which is the inheritance and development of the ancient Wu dialect. Nowadays, the Shanghai dialect varies within five dialect areas in terms of their ancient tones – Chongming, Liantang, Songjiang, Jiabao (Jiading and Baoshan), and the downtown area.

Throughout Shanghai's history, the population and settlements of residents in the downtown area have been quite complicated. In addition to the prevailing Shanghai dialect, other dialects such as the Ningbo, Shaoxing, Suzhou, Wuxi, and northern Jiangsu dialects, as well as Cantonese are still used in Shanghai and have ongoing influence today. 

Source: Shanghai Almanac 2023