Carrollian holography suggests that gravity in four-dimensional (4d) asymptotically flat spacetime is dual to a three-dimensional (3d) Carrollian CFT living at null infinity. In this talk, I will review this framework and explain how massless scattering amplitudes in flat space can be recast as Carrollian CFT correlators at null infinity, referred to as Carrollian amplitudes. I will show that these correlators arise naturally from the Carrollian limit of holographic CFT correlators computed via AdS Witten diagrams, establishing a correspondence between the flat-space limit in the bulk and the Carrollian limit at the boundary. As a concrete application, I will briefly discuss the flat-space/Carrollian limit of the duality between 11d supergravity on AdS_4xS^7 and the 3d ABJM theory. Based on arXiv:2312.10138, arXiv:2406.19343 and work in progress.