A wide range of research fields including medical science, medical diagnostics, materials science, environmental protection, and metrology would hugely benefit from better data and knowledge on nanoparticles. To meet this requirement, Nanosight has developed unique and innovative instruments for imaging and measuring individual nanoparticles. The instruments give data on particle size distribution, concentration, and aggregation, with much higher resolution, sensitivity and accuracy than has been previously possible. The addition of fluorescence and Zeta measurement options dramatically extends the capabilities of the instruments, allowing truly multi-parametric characterisation of nanoparticles. Endorsed by an exponential growth in scientists citing its use in scientific papers, and applicable in a wide range of fluids, including complex biological systems, the Nanosight system provides scientists with detailed data and knowledge of nanoparticle systems that was previously unavailable.