The chemical oxidative polymerization and electrochemical polymerization of 3-aminobenzenesulfonic acid with aromatic amines have been carried out in p-toluenesulfonic acid which acts as a supporting electrolyte as well as an external dopant. The presence of –SO3H groups in the ABSA co-monomer allows the copolymer to acquire intrinsic protonic doping ability. The electrochemically synthesized polymers and copolymers have been characterized by cyclic voltammetry for analyzing the growth of copolymers and chronoamperometry studies for their applications to the electrochromic devices. In addition to construction of electrochromic devices (ECDs), the electrochromic properties of the polymer films were further investigated. Electrochromic switching stability of the devices was estimated from switching times between their oxidized and reduced states, which indicates that the homopolymers and copolymer can be used for promising electrochromic devices. Chemically synthesized copolymers were also characterized using various techniques like Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy and electrical conductivity at room temperature.