AbstractA new method to follow in‐situ grafting kinetics of diazonium compounds based on imposing small amplitude high frequency AC oscillations at grafting potential, is outlined. This enables the time‐resolved measurements of capacitive impedance concomitantly with the growth of the organic layer at the working electrode. The impedance values were quantitatively correlated with the ex‐situ (from voltammograms) and in‐situ (from quartz crystal microbalance) measured surface coverages, providing a validation of the new methodology. The versatility of the developed approach was demonstrated on the grafting via reduction of 4‐nitrobenzenediazonium on Au and glassy carbon (GC) substrates and via deposition of in‐situ generated diazonium salts from 1‐aminoanthraquinone and 4‐ferrocenylaniline on GC. The capacitive impedance measurements are simple, fast, and non‐destructive, making it an appealing methodology for an exploration of grafting kinetics of a wide range of diazonium salts.