An electrolyte for electrochromic devices is manufactured by mixing (210) a solvent, an ionisable substance and a solvated polymer. The solvent comprises a substance having an amide group and selected from a specified group of substances. The ionisable substance comprises an anion and a cation, where the cation preferably is selected among the alkaline ions. The anion is selected from simple anions, such as hydroxide ions, halide ions or more or less complex organic anions. The polymer is solvated in the mixture of the two other components.