The western European Alps display measurable surface deformation rates from levelling and GNSS data. Based on the time series analysis of 4 yrs of Sentinel-1 data, we propose for the first time an InSAR based mapping of the uplift pattern affecting the western Alps on a ~350x175 km wide area. This approach provides a denser spatial distribution of vertical motion despite the high noise level inherent to mountainous areas and the low expected deformation signal. Our results show consistency with other geodetic measurements at the regional scale, and reveal smaller scale spatial variations in the uplift pattern. Higher uplift rates are found within the external crystalline massifs than in the surrounding areas, in agreement with variations expected from recent deglaciation and long-term exhumation data. This work features the first geodetic clues of a differential present-day uplift response of crystalline massifs to surface and deep processes affecting the Alpine belt.