Gamma rays have the shortest wavelengths in the electromagnetic spectrum — typically less than 0.01 nanometers (nm), and often much smaller.
To be more precise:
- Common range: from about 10⁻¹¹ meters (0.01 nm) down to 10⁻¹⁶ meters or even shorter.
- In terms of picometers (pm): less than 10 pm.
Because gamma rays are defined mainly by their origin (nuclear or high-energy particle processes) rather than just wavelength, there’s no strict cut-off — but their wavelengths are always far shorter than those of X-rays, and their frequencies are extremely high (above 10²⁰ hertz).