What exactly is a DOI?
A DOI is a persistent identifier for a digital object, most often a journal article, dataset, book chapter or piece of software. It has two parts separated by a slash: a prefix beginning with 10. that identifies the registrant, and a suffix the registrant chooses.
10.5555/hydro.2025.017: prefix 10.5555, suffix hydro.2025.017, resolvable as https://doi.org/10.5555/hydro.2025.017
The DOI system is an international standard, ISO 26324, governed by the DOI Foundation. Its value is the promise behind it: whoever registered the DOI agrees to update where it points when the work moves, so a DOI printed in a reference list keeps working long after a website is redesigned. DOI names are not case-sensitive.
Who issues DOIs?
DOIs are issued by registration agencies, each serving a community. The two that matter most for research are:
- Crossref, used by journal and book publishers, conference organisers and many preprint servers. Most journal article DOIs are Crossref DOIs.
- DataCite, used by data repositories, research institutions and services such as Zenodo for datasets, software and other outputs.
Organisations join an agency as members, pay fees, and take on the duty of keeping metadata and target addresses current. Individuals cannot register DOIs directly; they get them through a publisher or repository that is a member.
How is a DOI different from a URL?
A URL says where something is now; a DOI names what it is and is redirected to wherever it is. If a publisher moves its journals to a new platform, every article URL changes, but the DOIs are updated to point at the new addresses and citations keep working.
A DOI also carries registered metadata (title, authors, dates, license and often references) in a central, openly queryable database. Discovery and bibliometric services use that metadata to link works, count citations and populate researcher profiles.
Other identifiers serve narrower purposes. An ISSN identifies a journal, an ISBN a book, an arXiv identifier or PubMed ID a record in one service, and an ORCID iD a person rather than a work. A Life of Research identifier such as LOR-00042 identifies a record in this repository and, with its permanent URL, is enough to cite it.
Do you actually need a DOI?
You need a DOI when someone requires one, and it helps when you want automated citation tracking. Typical cases:
- a journal's data policy asks for the underlying dataset to be deposited with a DOI;
- a funder's open-access or data policy names DOIs or "persistent identifiers";
- you want the work to appear in services that harvest Crossref or DataCite metadata, and to be counted by tools that track citations by DOI.
You do not need a DOI to be citable. APA, Chicago, Harvard and other styles all accept a stable URL when no DOI exists, and a repository URL that never changes, such as a Life of Research permanent link, does exactly that job.
How can you get a DOI without paying?
Most researchers get DOIs free through a service that already belongs to a registration agency:
- Journals assign a Crossref DOI to every article they publish.
- Zenodo, run by CERN, assigns a DataCite DOI to every deposit at no cost, including each software release synchronised from GitHub.
- Preprint servers such as arXiv, bioRxiv and medRxiv assign DOIs to posted preprints.
- Institutional repositories and university libraries with DataCite membership mint DOIs for their members' datasets and theses.
If you need a new DOI for work you deposit here, deposit it in a DOI-minting repository as well and enter that DOI on your Life of Research record, so both copies point to the same identifier.
How does Life of Research handle DOIs?
Life of Research does not mint DOIs, because that requires paid membership of a registration agency, which it does not currently have. Every record instead gets a permanent URL that includes its type, such as /articles/42, and an identifier such as LOR-00042 that is never reused.
When a work already has a DOI, enter it in the Publication details section of the deposit form. It is then shown on the record page as "registered elsewhere", linked through https://doi.org/, used in the APA and BibTeX citations, and included in the record's citation metadata and structured data, so search engines and reference managers connect the two copies.
How should you write a DOI in a reference?
Write the DOI as a full HTTPS link: https://doi.org/10.5555/hydro.2025.017. This is the form recommended by Crossref's display guidelines and by APA 7th edition, and it makes the DOI clickable in every PDF and web page. Older forms such as doi:10.5555/… or http://dx.doi.org/… still resolve but are no longer recommended in reference lists.
Copy DOIs rather than retyping them; a single wrong character sends readers to a different work or to an error page.