According to our current understanding of physics, photons are considered to be point-like particles, meaning they are believed to have no spatial extent or size. In other words, photons are considered to be elementary particles with zero physical size.
However, it is important to note that our understanding of the fundamental nature of particles is based on theoretical models and experimental observations, and our understanding could change as our knowledge advances. Some theories beyond the standard model of particle physics, such as string theory, propose the existence of extended or composite particles that could potentially have a non-zero size. But there is no experimental evidence or widely accepted theory suggesting that photons have a measurable radius.