Due to growing demand, the performance of traditional active carbon is insufficient. An innovative solution is superactive carbon with an ultra-high surface area as high as 3000 m2 g-1. However, this material is very costly due to the considerable amount of alkali used in its manufacturing. To obtain superactive carbon from lignin, KOH and KCl were used simultaneously. The method was thoroughly studied to describe the mechanism of pore origin and control the pore size. Because of synergy between KOH and KCl, superactive carbon with an ultra-high surface area (2938 ± 42 m2 g-1) was obtained at essentially diminished KOH consumption (1 g g-1) in contrast to previously reported methods. The process was optimised using the response surface method. The pore size can be tuned by varying the amount of KOH and temperature. Observed synergy enabled reduced alkali consumption, overcoming the barrier to widespread implementation of superactive carbon.