The straightforward electrochemically-initiated radical polymerization of three reactive monomers, i.e. 2,6-difluorophenyl acrylate (DFPA), pentafluorophenyl acrylate (PFPA), and glycidyl methacrylate (GMA), using a simple commercially available electrochemical setup for the generation of initiating radical species from 4-fluorobenzenediazonium tetrafluoroborate upon electrochemical cathodic reduction is reported. The use of a fluorine-labelled initiator allowed for the determination of number-average molar masses M_n of fluorine-containing polymers by ¹⁹F NMR spectroscopy in addition to size-exclusion chromatography. The obtained polymers were thereafter successfully subjected to post-polymerization modifications in order to emphasize the applicability of this polymerization method in regard to highly reactive monomers.