Structure search
Draw a molecule, paste a SMILES string, molfile or InChI, or upload a .mol file. Then search millions of chemicals by exact match, substructure or similarity.
It is a large download the first time, then it is cached.
Compounds that look alike, ranked by Tanimoto score
Signed out: first 20 results. Sign in free for up to 500.
How the three search types work
Pick the one that matches your question. You can switch and search again without redrawing.
Exact
Finds the very same compound from its standard InChIKey, and lists stereoisomers, isotope-labelled forms and charged forms separately.
Substructure
Finds every compound that contains your drawing, for example all pyridines or every molecule with a carboxylic acid on a benzene ring. Matches are shaded in the results.
Similarity
Ranks compounds by Tanimoto similarity of Morgan fingerprints. 100% means an identical fingerprint, around 70% still shares most of the scaffold.
The drawing editor is Ketcher by EPAM Systems (Apache 2.0 licence). Signed-out searches show the first 20 results, a free account shows up to 500.