Abstract <p>Many animals use a magnetic compass during migration, but data on its operation remain scarce. In amphibians, despite their great evolutionary significance, the compass type (inclination or polar) has been studied in only two species (common frog and red-spotted newt); moreover, no data exist on its light dependence in adult Anura. We previously found that breeding-stimulated marsh frogs respond to rotation of the horizontal magnetic field component by choosing the direction towards the spawning pond in a T-maze aligned with the natural migration axis. Now we tested their response to inversion of the vertical component; to investigate light dependence, experiments were conducted not only under white light but also in darkness. As a control for the breeding migratory state, experiments were performed in wintering state (total <i>N</i> = 554). Under light, breeding stimulated frogs oriented towards the ponds, altering their maze choice upon inversion of the vertical component, i.e., they used an inclination compass, as do the common frogs, newts, sea turtles and birds. In darkness, their choices were random. However, in wintering state, frogs chose the direction towards the river (wintering site) faster using the inclination compass in complete darkness. Consequently, our data do not provide a clear answer regarding the light dependence of the compass in marsh frogs, as the effect of darkness may have masked their orientation behaviour. No relationship between magnetic field orientation and the external development of one of its hypothetical receptors, the frontal organ, was found; however, definitive conclusions require more in-depth morphological and electrophysiological studies.</p> Significance statement <p>The mechanisms of magnetoreception remain highly debated. A prominent theory, the radical pair hypothesis, suggests that the compass should be inclinational and light-dependent. Despite the evolutionary significance of amphibians, data on their magnetic orientation are scarce. We extend research to a new species and provide the first experimental assessment of light dependence in adult anurans. Our results demonstrate that marsh frogs possess an inclinational compass but its light dependence remains unclear. We discuss the evidence for and against light dependence and evaluate the overall effect of illumination on frogs’ behavior. The hypothesis proposing a leading role for the frontal eye is not supported by our findings; however, definitive conclusions would require more in-depth morphological and electrophysiological studies.</p>