Numerical studies of various aspects of two‐dimensional Langmuir solitons, are made, viz., (i) instability and collapse of a planar soliton perturbed in the perpendicular direction, (ii) the effect of an approximate Landau damping on the collapse, and (iii) the generation and subsequent collapse of planar solitons by an external pump field. These computations verify the flow of energy from long wavelength pump fields, through soliton formation and collapse, to shorter wavelengths, where the energy is transferred to the electrons.