You have a DOI, you need a BibTeX entry, and copying fields out of the journal page by hand is how typos end up in bibliographies. The good news: every DOI already has machine-readable metadata behind it, so converting a DOI to BibTeX takes seconds. The catch is that the metadata is only as good as what the publisher deposited, which is why the second half of this guide is about checking the entry before you trust it.
Where to find the identifier
- DOI. Printed on the first page of most papers and on the journal's landing page. It always starts with
10.and looks like10.1038/s41586-020-2649-2. If you only have ahttps://doi.org/...link, the DOI is everything afterdoi.org/. - arXiv ID. For preprints, use the ID from the URL:
2401.12345(or the oldermath/0601001style). If the paper was later published in a journal, prefer the journal DOI so you cite the version of record.
Three ways to convert a DOI to BibTeX
1. A converter (fastest)
Paste the DOI or arXiv ID into Sidenote's free citation generator, choose BibTeX, and copy. It queries Crossref for DOIs and the arXiv API for preprints, and it can give you APA, MLA, Chicago, Harvard or RIS from the same lookup. No sign-up, and there's a Manual tab for the rare source with no identifier.
2. Ask doi.org directly (no tool needed)
The DOI system supports content negotiation: request the DOI with a BibTeX Accept header and you get the entry back.
curl -LH "Accept: application/x-bibtex" https://doi.org/10.1038/s41586-020-2649-2
Handy in scripts, and it's the same Crossref metadata a converter uses.
3. Export from arXiv or your reference manager
Every arXiv abstract page has an Export BibTeX Citation link in the sidebar. In Zotero, the "Add Item by Identifier" wand accepts a DOI or arXiv ID and creates the item, which you can then export as BibTeX. Mendeley and EndNote import RIS more cleanly, so pick that format there.
The five fields to check before you save
- Title capitalisation. Most BibTeX styles lowercase titles unless you protect words in braces:
{DNA},{Bayesian},{COVID-19}. - Authors. Confirm the order and that names came through as
Last, Firstpairs joined byand. Consortium authors often arrive mangled. - Journal and year. Some publishers deposit the abbreviated journal name, others the full one. Match whatever the rest of your bibliography uses.
- The
doifield. Keep it. Most modern styles print the DOI as a link, and it's the one field that makes your reference unambiguous. - The cite key. Converters generate keys like
smith2020title. Rename them to your own convention before the file grows.
For arXiv entries, keep the eprint and archivePrefix fields the export gives you, and if there's a published version, add its DOI rather than citing the preprint.
Importing the entry
| Where you write | What to do |
|---|---|
| LaTeX / Overleaf | Paste into your .bib file and cite with \cite{key} |
| Zotero | Import from clipboard, or use the identifier wand and export later |
| Mendeley / EndNote | Prefer RIS from the same converter; both import it without fuss |
| Word with a Zotero or Mendeley plugin | Import to the manager first, then insert from the plugin |
Reading the paper you just cited
A correct BibTeX entry is the last step; the first is reading the paper. If you read papers in the browser, Sidenote for research papers summarises and answers questions about the open PDF or arXiv page with a citation that scrolls to the exact passage, so the claim you're about to attribute to a paper is one you've actually verified in it. For the wider workflow, see how to cite a PDF and our roundup of Zotero plugins.