BRENDA, the Comprehensive Enzyme Information System, is an enzyme database curated at the Leibniz Institute DSMZ. It provides researchers, students, and other users with free online access to detailed information about enzymes, ligands, organisms, and related biochemical data. The database supports searches across a wide range of fields, including enzyme names and classifications, reactions, substrates and products, cofactors, inhibitors, kinetic parameters, structures, sequences, and organism or tissue sources.

Beyond standard and advanced text searches, BRENDA offers tools for ligand structure searches, metabolic pathway exploration, enzyme classification, organism and genome browsing, and visualization. Additional resources include enzyme and organism word maps, functional parameter statistics, pathway prediction, localization prediction, and links to protein-folding classifications and ontologies. Users can also access downloads and data interfaces, including SPARQL, SBML, and SOAP, and contribute information or submit relevant papers. BRENDA is updated through regular releases, with its 2026.1 release covering new and updated enzyme classes. The online database is available free under the CC BY 4.0 license, subject to its terms of use.