Strategic design of solid-state proton-conducting electrolytes for application in anhydrous proton-exchange membrane fuel cells (PEMFCs) has gained burgeoning interest due to a spectrum of advantageous features, including higher CO tolerance and ease in the water management systems. Toward this direction, crystalline materials like metal-organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs), and polyoxometalates (POMs) are emerging PEM materials, offering strategic structural engineering through crystallography, thus enabling ultrahigh anhydrous proton conductivity up to 10