A filling level sensing device for a liquid reservoir, in particular for a compensation tank of a vehicle brake system, includes at least one float, at least one sensor element connected to the at least one float, and at least two sensors for detecting the position of the at least one sensor element. The float may be designed to come into contact with the liquid in the liquid reservoir. At least one of the two sensors may sense a change in the filling level of the liquid reservoir depending on the position of the at least one sensor element relative to the at least two sensors.