SMILES (simplified molecular-input line-entry system) is a common method of specifying the structure of a molecule by arranging letters representing an atomic element into a string. MOL (or MDL Molfile) is a chemical table file similarly used to reflect the chemical structure of a molecule. A MOL file contains the atoms in a molecule with their specified coordinates, as well as the bonds that each has to one another.

This tool will convert a SMILES-formatted string or .smi file into a .mol file, or a MOL-formatted string, .mol file, or .mdl file into an .smi file.