Abstract: A multi-purpose convertible ladder stabilizer, particularly adapted to stabilize the upper free end of ladders such as the extension type during utility in the construction, maintenance, repair, painting of commercial and domestic buildings. The stabilizer is characterized by its portability and function convertibility wherein it may be removably set for disposition as an outside corner clutch, an inside corner engager, a building overhang ladder attachment, window spanner and the like. A coactive relationship is provided between elements wherein interconnected articulable extensions and a ladder during use, irrespective of the geometric vertical configuration of that elevated part of a building which may be considered the workplace.