In the title compound, C17H18N8, the imidazolidine ring adopts an envelope conformation with the substituents at the N atoms in trans positions with respect to the central ring. The dihedral angle between the two benzotriazole rings is 71.65 (10)°. In the crystal, non-classical C—H...N interactions link the molecules into helical chains along the b axis. The crystal packing is further stabilized by weak C—H...π interactions.