Carbene transfer reactions play an important role in the field of organic synthesis because of their abil-ity to construct a variety of molecules. Herein, we reported on blue light-induced cyclopropenizations of N-tosylhydrazones in water, which avoids the use of expensive metal-based catalysts and toxic organic solvents. This metal-free and operationally simple methodology enable highly efficient cyclopropeniza-tions, X-H insertion reactions, and cyclopropanation under mild reaction conditions.