What Is a DOI?
A DOI (Digital Object Identifier) is a permanent, unique identifier assigned to an academic article or dataset that always resolves to the published content, even if the URL changes.
Definition
A DOI (Digital Object Identifier) is a permanent, unique identifier assigned to a digital academic object — most commonly a journal article, but also datasets, books, conference papers, and software. A DOI takes the form 10.prefix/suffix and always resolves to the published content through the DOI.org resolver, even if the article moves to a different URL.
DOIs are the standard citation identifier in academic publishing. When you see a reference like doi:10.1016/j.cell.2023.01.001 in a paper, that DOI will resolve to the article no matter how many times the publisher's website changes.
How DOIs Work
DOIs are maintained by the International DOI Foundation (IDF) and registered through agencies like CrossRef, DataCite, and mEDRA.
When a journal registers a DOI:
- The publisher submits article metadata (title, authors, abstract, publication date, ISSN) to CrossRef
- CrossRef creates a record linking the DOI to the article's URL
- The DOI is printed on the article and in citation databases
- When someone clicks
https://doi.org/10.xxxxx/yyy, CrossRef's resolver redirects them to the current URL - If the URL changes, the publisher updates the redirect — the DOI never changes
DOI Requirements for Indexing
Most major indexing databases require or strongly prefer DOIs:
- CrossRef metadata — Required for Crossmark integration and citation tracking
- Scopus — Does not require DOIs but uses them for citation matching
- Web of Science — DOIs improve citation matching accuracy
- DOAJ — Requires CrossRef DOI registration for the DOAJ Seal
- Google Scholar — Indexes articles more reliably when DOIs are present
- PubMed — Requires NLM/DOI metadata for indexed journals