The method for manufacturing timepiece hairsprings according to the invention comprises the following successive steps: a) forming hairsprings in a wafer, b) forming a thermal compensation layer on the hairsprings, c) identifying the hairsprings having a stiffness within a predetermined range, d) optionally, detaching from the wafer the hairsprings identified in step c), e) modifying the other hairsprings so that the stiffness of at least some of them is within the predetermined range, f) detaching from the wafer these other hairsprings and, if they have not been detached in step d), the hairsprings identified in step c). This method makes it possible to reduce manufacturing dispersions between the hairsprings.