The Compounds API is our only set of publically available production-ready endpoints, however, we provide a set of "Demo" endpoints that showcase data and features that we are testing out. These Demo endpoints are not designed for production use and often work for a limited set of cases, howeverw if you are interested in any of the demo APIs please do get in touch with us - we are constantly looking to improve and expand the services that we offer to the Chemical Sciences community and plan to offer more API solutions in the future - if you would like to suggest new services that you would like to see, we welcome your feedback

Interrogate and access chemical data, powered by the Royal Society of Chemistry's ChemSpider database.

A set of APIs for developers to explore, these are all demonstration endpoints (and are not designed for Production use). These APIs showcase services that we might develop and are provided for testing and feedback. In most cases the APIs only provide meaningful results for a small subset of queries/data points.



Compare with the old ChemSpider APIs

ChemSpider Search API New API  (
AsyncSimpleSearch (input: Name) /filter/name
AsyncSimpleSearch  (input: InChI) /filter/InChI
AsyncSimpleSearch (input: InChIKey) /filter/InChIKey
AsyncSimpleSearch (input: SMILES) /filter/SMILES
AsyncSimpleSearchOrdered (input: Name) /filter/name
AsyncSimpleSearchOrdered (input: InChI) /filter/InChI
AsyncSimpleSearchOrdered (input: InChIKey) /filter/InChIKey
AsyncSimpleSearchOrdered (input: SMILES) /filter/SMILES
CSID2ExtRefs /records/{recordId}/externalreferences
GetAsyncSearchResultPart /filter/{queryId}/results
GetAsyncSearchStatus /filter/{queryId}/status
GetAsyncSearchStatusAndCount /filter/{queryId}/status
GetCompoundInfo /records/{recordId}/details
GetCompoundThumbnail  /records/{recordId}/image
GetRecordDetails /records/{recordId}/details
IntrinsicPropertiesSearch /filter/intrinsicproperty
SimpleSearch  (input: Name) /filter/name
SimpleSearch (input: InChI) /filter/InChI
SimpleSearch (input: InChIKey) /filter/InChIKey
SimpleSearch (input: SMILES) /filter/SMILES
SimpleSearch2IdList /filter/name


ChemSpider InChI API New API  (
CSIDToMol /records/{recordId}/mol
InChIKeyToCSID /filter/InChIKey
InChIKeyToInChI /tools/convert
InChIKeyToMol /tools/convert
InChIToCSID /filter/InChI
InChIToInChIKey /tools/convert
InChIToMol /tools/convert
InChIToSMILES /tools/convert
IsValidInChIKey /tools/validate/InChIKey
MolToInChI /tools/convert
MolToInChIKey /tools/convert
SMILESToInChI /tools/convert


ChemSpider MassSpec API New API  (
GetCompressedRecordsSdf /filter/{queryId}/results/sdf
GetDatabases /lookups/datasources
GetExtendedCompoundInfo /records/{recordId}/details
GetExtendedCompoundInfoArray /records/batch
GetExtendedMolCompoundInfoArray /records/batch
GetFormulaArrayAsyncSearchResultPart /filter/formula/batch/{queryId}/result
GetMassArrayAsyncSearchResultPart /filter/mass/batch/{queryId}/results
GetRecordMol /records/{recordId}/mol
SearchByFormula /filter/formula
SearchByFormula2 /filter/formula
SearchByFormulaArrayAsyncOrdered /filter/formula/batch
SearchByFormulaAsync /filter/formula
SearchByFormulaAsyncOrdered /filter/formula
SearchByMass /filter/mass
SearchByMass2 /filter/mass
SearchByMassArrayAsyncOrdered /filter/mass/batch
SearchByMassAsync /filter/mass
SearchByMassAsyncOrdered /filter/mass