Fixed target experiments are excellent tools for searching for signals of weak interacting dark matter in the sub-GeV mass region. The concept of dark portals between hidden and ordinary matter, as described by the Standard Model, typically involves light sub-GeV intermediate states. In particular, the dark photon portal will be considered and discussed within the framework of existing and future experiments, such as NA64 at the SPS at CERN. Besides, beam dump mode experiments are also tools for studying visible modes of dark matter. We will discuss the current experimental situation and which models and properties are being studied using such experiments.