The Identifiers.org resolution system provides consistent access to life science data using Compact Identifiers (CIDs). Compact Identifiers minimally consist of an assigned unique prefix and the accession number designated by the data provider (prefix: accession). CIDs can currently be dereferenced by 2 meta resolvers: identifiers.org and n2t.net. The final resolving location, using either meta resolver, is ultimately determined using information that is stored in the Identifiers.org Registry, which contains high quality, manually curated information on over 700 data resources (largely databases). In addition to resolution, Identifiers.org provides a number of additional services, including the ability to harvest and display schema.org (and bioschemas) metadata markup, using with ‘dataset’ and ‘data record’ profiles, through an Identifiers.org metadata service.