Radio waves and visible light are both forms of electromagnetic radiation, and they travel through a vacuum at the same speed: the speed of light, which is approximately 299,792 kilometers per second (or about 186,282 miles per second).
Though they occupy different parts of the electromagnetic spectrum, all electromagnetic waves, including radio waves and visible light, propagate at this constant speed. The difference lies in their wavelengths and frequencies; radio waves have longer wavelengths and lower frequencies compared to visible light.
This means that, while both types of waves travel at the same speed in a vacuum, their characteristics differ, impacting their use in various technologies. For instance, radio waves are excellent for communication over long distances, while visible light is crucial for human vision and is utilized in applications ranging from photography to fiber optics.