New generation of thin-film transistors (TFTs), where the active material is amorphous oxide, conjugated polymer, or small molecules, have the advantage of flexibility, high form factor, and large scale manufacturability through low cost processing techniques, e.g., roll-to-roll printing, screen printing. During high-throughput production using these techniques, the probability of defects being present increases with the speed of manufacturing and area of devices. Therefore a high-throughput and low cost testing technique is absolute essential to maintain high quality of final product. We report a Simultaneous Multiple Device Testing (SMuDT) approach which is up to 10 times faster and cost effective than conventional testing methods. The SMuDT approach was validated using circuit simulation and demonstrated by testing large scale indium gallium zinc oxide (IGZO) TFTs. A method to ‘bin’ the tested devices using Figure of Merit was established.