Abstract We apply burst vibrothermography to characterize (area and depth) vertical cracks in a fast way. We present the calculation of the evolution of the surface temperature distribution produced by a vertical crack excited by an ultrasound burst. We develop a stabilized inversion algorithm that is able to retrieve the area and depth of the crack from one thermogram and one timing-graph. We check its performance by inverting both, synthetic data and experimental data taken on samples containing calibrated heat sources. Depth limits are established for accurate reconstructions of the defects as a function of the noise in the data.