Wavefront measurements are important in many fields of applied optics such as wavefront control of laser beams, optical diagnostics of the surface, human-eye aberration measurements, etc. The sensor, based on the Talbot effect, can be a good alternative to the Shack–Hartmann sensor. A modified method of shearing grating interferometry is presented.This novel method allows measuring of freeform wavefronts with high accuracy. The experimental results are obtained using a binary amplitude grating and a spatial filter for the zero order. The filtering of the zero diffraction order results in an improved contrast and measurement performance. By means of robust and fast software, we are able to precisely reconstruct the wavefront. A comparison of this method with Shack Hartmann Sensor (SHS) is presented.