The world's smallest QR code is only visible with an electron microscope. Credit: TU Wien How small can a QR code get? A team of researchers has pushed the limits to an extreme, creating one so tiny it can only be detected using an electron microscope. Scientists at TU Wien, working with data storage company Cerabyte, produced a QR code measuring just 1.98 square micrometers, which is smaller than most bacteria. This achievement has now been officially confirmed and recorded in the Guinness