<p>Reliable measurement of gate-dependent mobility is essential for understanding charge transport in organic mixed ionic–electronic conductors (OMIEC), yet current methodologies remain poorly standardised. Here, we propose and validate two complementary approaches for mobility extraction in organic electrochemical transistors: gate-dependent impedance matching and gate-dependent time-of-flight. Through comprehensive benchmarking across representative OMIEC systems, we demonstrate that both techniques provide consistent and accurate mobility profiles throughout the full operational regime of the devices. Furthermore, we identify key experimental parameters that determine measurement fidelity, establishing standardised practical guidelines that can serve as a robust framework for reliable mobility extraction across diverse OMIEC platforms.</p> Graphical abstract <p></p>