A method for contactless measurement of the speed and/or the length of a strand, especially of a cable, moved forward lengthways, during production, characterized by the following steps: - a first optical beam is oriented on one side transversely to the strand and received by a first receiving surface of a first image sensor at a predetermined first location on the opposing side of the strand, - at predetermined times, the first diffraction patterns imaged at the shadow boundaries on the first receiving surface are analysed for at least one specific feature characterizing the surface contour and the feature characterizing the surface contour is stored, - a second optical beam oriented transversely to the strand is oriented toward a second receiving surface of the first or a second image sensor, said second receiving surface being arranged in the advancing direction of the strand at a second location which is on the same side as the first receiving surface and which is spaced apart from the first location of the first receiving surface, - second diffraction patterns imaged at the shadow boundaries on the second receiving surface are analysed for at least one feature characterizing the surface contour, - in an evaluation device it is determined after which time interval a characterizing feature of a first diffraction pattern detected on the first receiving surface correlates approximately with a characterizing feature of a second diffraction pattern detected on the second receiving surface, - the advancing speed of the strand and therefrom the advanced length of the strand is determined from the distance between the receiving surfaces (30, 32) or respectively the imaging locations of the characterizing feature of the first and second diffraction patterns (36, 38) on the receiving surfaces (30, 32) and the time interval. - a first optical beam is oriented on one side transversely to the strand and received by a first receiving surface of a first image sensor at a predetermined first location on the opposing side of the strand, - at predetermined times, the first diffraction patterns imaged at the shadow boundaries on the first receiving surface are analysed for at least one specific feature characterizing the surface contour and the feature characterizing the surface contour is stored, - a second optical beam oriented transversely to the strand is oriented toward a second receiving surface of the first or a second image sensor, said second receiving surface being arranged in the advancing direction of the strand at a second location which is on the same side as the first receiving surface and which is spaced apart from the first location of the first receiving surface, - second diffraction patterns imaged at the shadow boundaries on the second receiving surface are analysed for at least one feature characterizing the surface contour, - in an evaluation device it is determined after which time interval a characterizing feature of a first diffraction pattern detected on the first receiving surface correlates approximately with a characterizing feature of a second diffraction pattern detected on the second receiving surface, - the advancing speed of the strand and therefrom the advanced length of the strand is determined from the distance between the receiving surfaces (30, 32) or respectively the imaging locations of the characterizing feature of the first and second diffraction patterns (36, 38) on the receiving surfaces (30, 32) and the time interval.