Modeling nanoparticles is an essential first step to assess their capacity in different uses such as in energy storage or drug delivery. However, creating an initial starting conformation for modeling and simulation is tedious because every crystalline material grows with a different crystal habit. In this application note, we describe Nano-Crystal, a novel web-based crystallographic tool, which creates nanoparticle models from any crystal structure guided by their preferred equilibrium shape under standard conditions according to the Wulff morphology (crystal habit). Users can upload a cif file, define the Miller indices and their corresponding minimum surface energies according to the Wulff construction of a particular crystal, and specify the size of the nanocrystal. As a result, the nanoparticle is constructed and visualized, and the coordinates of the atoms are output to the user. Nano-Crystal can be accessed and used at http://nanocrystal.vi-seem.eu/.