LHC started to test directly produced electroweak particles in the multi-hundred GeV range, if they decay to a long lived massless particle. Scenarios with a smaller mass splitting are instead much more challenging to be probed. In this talk, after a brief review of models with a compressed spectrum, I discuss the several techniques one could use to test scenarios with a mass splitting in the range (0 - 40) GeV. In particular, I will focus on the role of a relatively hard initial state radiation jet. Some emphasis will also be dedicated to the intriguing possibility of having production of electroweak particles through the decay of the 125 GeV Higgs boson.