DOI to BibTeX Converter
Paste DOIs, one per line, and get BibTeX entries ready for LaTeX, Overleaf, JabRef or Zotero: author names as Last, First, capitals in titles protected with braces, pages with a double dash, and unique cite keys such as lecun2015deep.
- Free, no sign-up, no limits
- Checks 5 free scholarly databases
- Nothing stored by LetRelay
Word (.docx), .bib, .ris and .txt files work. Each reference is looked up in free public databases; nothing is stored by LetRelay.
How to use it
Paste your DOIs
One per line. Whole references work too: each is found in the databases first.
Check the matches
Every DOI shows its paper, so you can see it is the right one.
Copy the BibTeX
Copy the entries or download a .bib file for Overleaf, JabRef or Zotero.
The details come from the publisher's own record, and a DOI that does not exist is flagged instead of turned into a broken entry.
Straight from the publisher's record
A DOI is registered by the publisher with the work's details, so a citation made from it is as accurate as the publisher's own record. Each DOI is read from Crossref (journals, books, conference papers) or DataCite (arXiv, Zenodo and repositories). If neither has it, doi.org says whether the DOI exists at all: one that does not exist usually has a typo, or was invented by an AI tool.
How each reference is checked
Most reference checkers either only look at punctuation, or send your list to an AI that can itself make things up. This one looks every reference up in the published record, and only calls it found when a record agrees on both the title and the authors. The databases, all free and public, are asked in this order, cheapest and most exact first:
| Database | What it holds | Used for |
|---|---|---|
| doi.org | Every DOI ever registered, with any agency | Does the DOI in your reference exist at all? |
| Crossref | 188 million records: journal articles, books, chapters and conference papers with a DOI | The DOI's own record, and matching the whole reference as written |
| Europe PMC | 49 million records, including all of PubMed and PubMed Central, and preprints | Medicine and life sciences, also papers without a DOI |
| DataCite | arXiv, Zenodo, figshare, Dryad and university repositories | Preprints, datasets and theses |
| Open Library | Books, with every edition and printing | Books that have no DOI |
| OpenAlex | 318 million works from all of the above and more | Anything the others missed, and retraction flags |
When a record matches, the year, DOI, journal, volume and pages are compared with what you wrote. A different year is only called wrong when the journal, volume or pages confirm it is the same publication, and for books it is never called wrong, because editions and reprints carry their own years. Matched papers are checked for retractions with the Retraction Watch database (part of Crossref since 2023).
What the results mean
- Verified: a published record agrees with the reference on title, authors and year. Nothing to change.
- Found, with fixes: the work exists, but something in your reference is wrong (year, DOI, first author, journal, volume or pages). The correct value is shown next to yours, and the finished list uses it.
- Retracted: the work exists but has been retracted, withdrawn or given an expression of concern. Do not rely on it.
- Does not match: the title exists under other authors, or the DOI belongs to a different work. This is how AI-made references often look.
- Check this one: a close record was found but something important differs. Open it and say yes or no.
- Not found: no database has it. It may be invented, or a source they do not cover (an unpublished thesis, a report, a web page, a paper from the last few days). Search Google Scholar with one click before you keep it.
What it cannot do
No free database holds every source, so the tool never calls a reference fake: it says not found and tells you where to look. It cannot see whether a paper says what you cite it for; it proves the paper exists and is cited correctly, so read the part you rely on. Web pages, laws, standards and most reports are not in paper databases, so those are labelled rather than checked. Titles are put in sentence case for APA, Vancouver and IEEE; a program cannot always tell a name from an ordinary word, so check capitals in names of places, methods and software. Your own titles keep your capitals unless you ask otherwise.
How we tested it
Before release it was run against 56 references in APA, Harvard, Vancouver, IEEE, Chicago and MLA, from biology, medicine, psychology, economics, computer science and sociology: 40 real journal articles, conference papers, books, chapters and preprints; two well-known retracted papers; four real papers with one deliberate error each (a year, two DOIs, an author list); and ten references invented the way AI chatbots invent them. 38 of the 40 real works were found and verified. The other two: a WHO report, labelled as a report because paper databases do not list reports, and the 2014 conference paper that introduced GANs, which no free database lists under its published title (it came back “not found”, or “check this one” when OpenAlex was available, which is why not found never means fake). Both retractions were flagged, all four deliberate errors were caught, and none of the ten invented references was accepted. The formatting of every style was compared with the official CSL style files run by citeproc-js, the engine inside Zotero and Mendeley: 189 style and record pairs come out identical, and the rest differ only where we follow the style guide on purpose.
More free reference tools
The same engine, set up for a different job: Reference checker, Citation checker, AI citation checker, DOI to citation generator, BibTeX to APA converter, APA to Vancouver converter, BibTeX to RIS converter and RIS to BibTeX converter. Writing a thesis? The dissertation word count breakdown splits your word limit by chapter, and the PhD Gantt chart maker plans the time.
Frequently asked questions
How do I get BibTeX from a DOI?
Paste the DOI above and press Make BibTeX. The entry is built from the Crossref or DataCite record: the right entry type (@article, @inproceedings, @book, @incollection), all authors, title, journal or book title, year, volume, number, pages and DOI.
Can it convert many DOIs at once?
Yes, up to 500 in one go, into one .bib file with no duplicate cite keys (a second lecun2015deep becomes lecun2015deepa).
Why are some words in braces?
BibTeX styles often lower-case titles. Braces around words with capitals inside them (AlphaFold, ImageJ, BERT, DNA) keep those capitals in your PDF. Ordinary words are left alone so the style can do its job.
Does it work with Overleaf?
Yes. Download the .bib file and upload it to your Overleaf project, or copy the entries into the .bib file you already have. Cite them with \cite{key}.
What about arXiv papers?
arXiv DOIs (10.48550/arXiv.1706.03762) come from DataCite and become @misc entries with eprint and archiveprefix fields, which biblatex and most BibTeX styles print as an arXiv preprint.
Is it free?
Yes. There is no sign-up, no daily limit, no watermark and no paid tier. The databases it asks are free public services, called straight from your browser, so checking costs LetRelay nothing and there is nothing to charge for.