Extent-based kinetic identification is a kinetic modeling technique that uses concentrations measurements to compute extents and identify reaction kinetics by the integral method of parameter estimation. This article considers the case where spectroscopic data are used by calibration models to predict concentrations measurements. The calibration set is assumed to be constructed from reacting calibration data formed by pairs of concentrations and spectral data or concentration- and spectral contributions of reaction and mass transfer only, obtained by pretreatment in reaction- and mass-transfer-variant form. The extent-based kinetic identification using concentrations predicted by calibration models from spectroscopic data is illustrated by the simulation of a homogeneous and a gas-liquid reaction system.