A longitudinal folding apparatus for webs on a folder of a rotary press includes a variable-position folding former arranged behind a former roll and ahead of folding rolls in the web running direction, it being possible to adjust the folding former approximately in parallel in the direction of longitudinal axes of the folding rolls. The folding former is connected in a hinged fashion to levers which are mounted pivotably in the frame, the levers being drive-connected to one another.