The wavelength with the highest frequency is the one with the shortest wavelength. This is because frequency and wavelength are inversely proportional, meaning that as one increases, the other decreases.

The electromagnetic spectrum includes a wide range of wavelengths, from long radio waves to short gamma rays. The wavelengths with the highest frequencies are gamma rays, followed by X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves.

Gamma rays have the shortest wavelengths and the highest frequencies, followed by X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves.

Therefore, the wavelength with the highest frequency is gamma rays.