Herein, we analyzed the contents, properties, and chemical diversity of fragment libraries obtained from the latest releases of COCONUT and LANaPDB, CRAFT, and commercial fragment libraries. It was concluded that NPs have the highest percentage of unique fragments and "Fragments RO3." These results highlight the great structural diversity provided by the NPs. Also, NP fragments had higher values of sp and fraction of chiral carbons than the reference fragment libraries ChemDiv, Maybridge, Enamine, and Life Chemicals. Similarly, CRAFT fragments and "Fragments RO3" had the highest percentage of unique fragments as compared to the fragment libraries derived from COCONUT and LANaPDB. It was also found that the fragments from NPs (including the one that complies with the RO3), had a similar number of heterocycles and carbons, and similar values of nitrogens, oxygens, sp 3, and chiral carbon fraction, meaning that NP fragments retained structural features and complexity features of NPs from which they are derived. We also found that "Fragments RO3" from COCONUT were the most structurally diverse (as quantified using molecular fingerprints), meaning that the filters of the RO3 reduced the total number of