This paper reports on the first use of an in situ electrochemical strain gage method for the monitoring of the mechanical properties of conducting and redox electroactive polymers as they are switched between their neutral and oxidatively doped forms. Electrodeposition of three conducting polymers, specifically polypyrrole (PPy), poly(3,4-ethylenedioxypyrrole) (PEDOP), and poly[3,6-bis(2-(3,4-ethylenedioxy)thienyl)-N-carbazole] (PBEDOT-Cz) onto gold-coated strain gages allowed direct comparison of their actuation properties. It was found that the electromechanical response of PPy was significantly larger than either PEDOP or PBEDOT-Cz. This is attributed to the ability of PPy to cross-link at the open 3- and 4-positions of the heterocycle ring during electropolymerization.