High neural selectivity is an important indicator of how well a neural electrode will perform in a clinical setup. Among other factors, neural selectivity of an electrode strongly depends on its implant location. Today, the neural selectivity is evaluated by performing animal experiments and consequent offline analysis. The most selective electrode implant location is therefore difficult to predict. Here we developed a software tool to characterize neural electrodes' selectivity in real-time, in vivo. A graphical user interface (GUI) allows controlling the software tool. Our tool is adapted to use a commercially available neurostimulator (TDT, Tucker-Davis Technologies, US) but can be easily adapted to other systems. Electromyographic ( EMG) recruitment curves and selectivity indexes (SIs) were obtained stimulating the sciatic nerve of four pigs. The functionality, execution time of stimulation and correct SI calculation by the software-platform were evaluated by testing twelve intraneural electrodes.