The local In distribution in InGaN quantum wells was measured in samples which were grown by metalorganic vapor phase epitaxy (MOVPE) and molecular beam epitaxy (MBE) varying systematically the metal-flux ratio and the growth rate. The composition analyses were performed by local lattice parameter measurements based on lattice-fringe transmission electron microscopy (TEM) images. Composition fluctuations are observed in all samples on two typical scales: In-rich clusters with lateral sizes below 5 nm with high In concentration and weaker composition fluctuations on a 100 nm scale. The size of the clusters does not depend on the growth conditions, but the amplitude of the composition fluctuations is influenced by the growth rate. In-concentration profiles along the growth direction show the effect of In desorption and In segregation during the growth.