The title molecule, C24H23N3, shows some delocalization of charge based on the small [8.0 (2)°] angle between the indolin-2-ylidene ring system and the link methyldiazene C2N2 atom plane. A further twist of 17.2 (3)° is subtended between the C2N2 plane and its attached benzene ring. The dihedral angle between the biphenyl rings is 47.96(14)°. In the crystal, the molecules pack via C—H...π attractive interactions.