Wave folding is a type of wave shaper that creates complex, harmonically rich waveforms. It is often employed in modular synthesizers and is also used in some FM and Wavetable synthesizers.

When the input amplitude of a waveform exceeds a threshold, it usually clips, but in wave folding, it folds back on itself. This folding action amplifies and distorts the peaks and valleys of the waveform, introducing new harmonic content. As a result, the output waveform becomes more complex and intricate with added harmonic and tonal changes.