Understanding how gravity works on scales larger than the Solar system is one of the biggest challenge of modern cosmology. Some interesting results have been found in recent experiments, like PLANCK, and more precise tests will be enabled by ongoing and future large-scale surveys. In this context the search for efficient ways to test systematically a broad class of gravity theories is crucial to succeed in probing gravity with cosmological data. In this talk I will summarize the state-of-the-art of the cosmological gravity constraints, I will present the Effective Field Theory of Dark Energy (EFT) as promising framework to explore gravity theories and I will show some of the results we can obtain by applying this formalism.