AbstractHighly porous materials with a 3D framework have been produced by a sustainable salt template‐assisted chemical activation approach based on the use of KCl particles as template, K2CO3 particles as both template and activating agent, and biomass‐derivatives as carbon precursor (i. e., glucose and soybean meal). The self‐assembly of all the constituents into a 3D structure is achieved by a freeze‐drying process. After carbonization and a simple washing step with water, a 3D hierarchical porous carbon is obtained. The sustainability of the process is ensured by using chemicals of low or null toxicity and renewable carbon precursors. The materials produced are characterized by a 3D framework composed of thin walls rich in micropores, with BET surface areas in excess of 2000 m2 g−1 and pore volumes of up to 1.4 cm3 g−1. These materials show an improved rate capability in supercapacitors based on aqueous (H2SO4 and Li2SO4) and ionic liquid electrolytes (EMImTFSI/AN) with carbon electrode loadings well within the range of commercial values.