18 This paper aims to compare models from terrestrial laser scanning (TLS), 19 terrestrial photogrammetry (TP), and unmanned aerial vehicle photogrammetry 20 (UAVP) surveys to evaluate their potential in cliff erosion monitoring. TLS has 21 commonly been used to monitor cliff-face erosion (monitoring since 2010 in 22 Normandy) because it guarantees results of high precision. Due to some 23 uncertainties and limitations of TLS, TP and UAVP can be seen as alternative 24 methods. First, the texture quality of the photogrammetry models is better than 25 that of TLS which could be useful for analysis and interpretation. Second, a 26 comparison between the TLS model and UAV or TP models shows that the mean 27 error value is mainly from 0.013 to 0.03 m, which meets the precision 28 requirements for monitoring cliff erosion by rock falls and debris falls. However, 29 TP is more sensitive to roughness than UAVP, which increases the data standard 30 deviation. Thus, UAVP appears to be more reliable in our study and provides a 31 larger spatial coverage, enabling a larger cliff-face section to be monitored with a 32 regular resolution. Nevertheless, the method remains dependent on the weather 33 conditions and the number of operators is not reduced. Third, even though UAVP 34 has more advantages than TP, the methods could be interchangeable when no 35 pilot is available, when weather conditions are bad or when high reactivity is 36 needed. 37