Today, smartphone-based digital colorimetry is used as an inexpensive and portable tool. In this study, electro-Fenton (EF) method was coupled with a smartphone for acid fuchsine (AF) dye removal. In this method, the colored sample was photographed before and after the EF process. Then, the Red, Green, and Blue (RGB) and Hue, Saturation, and Value (HSV) codes of the image were extracted using Color Grab software. Experimental parameters were optimized by the central composite design (CCD). Optimized parameters were pH = 3, voltage = 20 V, time = 12 min, C H2 O2 = 10-5 mol L -1. Under these conditions, 96.2% AF removal was attained. The chemical oxygen demands (COD) evaluated by the EF processes were in good agreement with each other. In this EF system, a 65% decrease in COD was observed after 12 min.
