To measure the interface friction angle between two layers of geosynthetics at low normal stresses, the standard EN ISO 12957-2, using an inclined plane device, can be followed. The principle of this standard consists in increasing the shear stress until the sliding of the interface. The main objective of this study is to compare this loading method with the one of the shear box that consists in increasing the displacement at constant rate while recording the shear stress. Two geosynthetic – geosynthetic interfaces were selected. The first one consists of a non-woven geotextile onto a polypropylene PP geomembrane and the second one consists of a drainage geocomposite onto the same PP geomembrane. Two metric scale devices were used, an inclined plane device and a shear box. Friction tests were performed with the same normal stress of 5 kPa. The results show that the shear box test enabled safer friction angles than the inclined plane test.