Compact objects like neutron stars and black holes host extreme conditions that cannot be replicated in terrestrial laboratories or even by the most ambitious future particle colliders. These conditions make them unparalleled natural laboratories for exploring new physics. Among these, neutron stars stand out due to their incredibly strong electromagnetic fields, some of the most intense in the universe. This makes them ideal for testing the limits of (quantum) electrodynamics and probing physics beyond the Standard Model, including the search for axions—one of the leading candidates for dark matter. In this talk, I will highlight recent advancements in using pulsars to detect axions and discuss ongoing efforts to probe axions using magnetars, ultra-magnetic neutron stars that are the most magnetic objects in the Universe.