An injector testing device includes a fluid pump, which is configured to convey a test oil; a motor, which is connected mechanically to the fluid pump and is configured to drive the fluid pump; at least one injector holding device for mounting at least one injector to be tested; and a rail, which is configured to receive the test oil conveyed by the fluid pump and to fluidly connect to at least one injector to be tested. In this context, the rail is mounted in the injector testing device in such a manner, that it may be swiveled with respect to the at least one injector holding device, in order to align it with the injector to be tested.