Activated N/P codoped carbon (A-NPC) materials with ultrahigh specific surface areas (SSA) and hierarchical porous structures were synthesized by a green and cheap method to enhance the electrochemical performance of electrical double-layer capacitors. Waste durian peel was used as a carbon precursor, (NH4)(2)HPO4 as N and P sources, and KOH as an activator. The obtained porous carbon material had an ultrahigh SSA (3416 m(2) g(-1)), a hierarchical porous structure (84 vol % micropores), and appropriate N (2.17 at. %) and P (0.48 at. %) doping amounts. Synergy among these characteristics enabled the A-NPC to exhibit exciting specific capacitance (383.4 F g(-1) at 0.5 A g(-1)), ideal rate performance (255.6 F g(-1) at 20 A g(-1)), and fantastic cyclic performance (98.3% capacitance retention after 10 000 cycles at 5 A g(-1)) in the three-electrode device. This material could provide an energy density of 25.3 W h kg(-1) when the power density was 400.5 W kg(-1), to all-solid-state symmetrical capacitors and presented good cycle performance with a cycle retention rate of 97.6% at 2 A g(-1) after 5000 cycles. A-NPC has potential applications in the supercapacitor field given its excellent properties.