DOI to Citation Generator

What this tool does

One DOI in. APA, MLA, Chicago, and BibTeX out. One fetch, to CrossRef, sent from your browser. Nothing else leaves the page.

This is for the moment you already have the DOI and need the citation right now, in this style, into this draft. Opening a full reference manager for one paper is overkill. Most browser-based generators upload your DOIs to a server they control. This one does not: the only outbound request is the single GET to api.crossref.org you can watch in DevTools.

What is a DOI citation generator?

A DOI citation generator turns a Digital Object Identifier into a formatted reference. The input is a DOI in any common form: the bare string (10.1126/science.169.3946.635), a doi.org/ URL, or a citation block with a DOI embedded inside. The output is one or more reference strings ready to paste into a manuscript, bibliography, or .bib file. This generator outputs four styles simultaneously: APA 7th edition, MLA 9th edition, Chicago author-date, and BibTeX.

How this DOI converter works

Three things happen, and only three:

1. The text you paste is run through the official DOI regex (10.\d{4,9}/[-._;()/:A-Z0-9]+, case-insensitive) so any wrapping text (a doi.org/ prefix, a citation block, surrounding quotes) is stripped off and the bare DOI is extracted.
2. Your browser sends a single GET https://api.crossref.org/works/{doi} request. No API key, no authentication, no Fynman intermediary. The request goes from your browser to Crossref and back.
3. Four CSL formatters run on the returned JSON, in your browser, and render the four output panels.

The privacy badge at the top of this page hosts a live network counter that increments every time something leaves the tab. If the counter says one request per DOI fetched and zero otherwise, that is the entire network surface.

DOI to APA: what the tool outputs and how to tweak it

APA 7 follows author-date with sentence-case article titles, italic journal titles, italic volume number, non-italic issue in parentheses, and a DOI link at the end. For the worked example 10.1126/science.169.3946.635 the APA panel renders:

1

Hardin, G. (1968). The tragedy of the commons. Science, 162(3859), 1243-1248. https://doi.org/10.1126/science.162.3859.1243

A few things the formatter handles automatically: ampersand between the final two authors, year-only date (APA 7 dropped month and day for periodicals), no issue parenthesis when the journal uses continuous pagination across a volume. One thing it does not handle, because it cannot: hanging indent. That is a paragraph property in Word or LaTeX, not text inside the citation string. Set it once in your document and forget it.

DOI to MLA: what the tool outputs and how to tweak it

MLA 9 uses full first names where they exist, article title in quotation marks, journal title in italics, volume and issue with the abbreviations vol. and no., year, page range, and DOI rendered as a https://doi.org/ URL.

The Works Cited header that MLA expects above the reference list is your job, not the tool’s. The tool produces the entry; you produce the section. The same is true for hanging indent. If the source has a single author with a hyphenated last name or a particle prefix (von, de, al-), check the CrossRef record linked beneath the panel. Publishers deposit these inconsistently, and the formatter prints what CrossRef stored.

DOI to Chicago: author-date by default

Two Chicago systems exist: author-date (parenthetical citations, used by most sciences and social sciences) and notes-and-bibliography (footnote markers, used by most humanities). This tool outputs author-date by default, because the DOI workflow is overwhelmingly a sciences-side workflow and that is where the input volume lives. The format follows the Chicago Manual of Style, 17th edition.

To convert an author-date entry to a notes-and-bibliography footnote, change the leading Author, A. to A. Author (first-name-first), drop the year out front, and move it after the publisher. The page range becomes specific to the citation context. The tool does not do this transformation for you, but the author-date output gives you every field you need.

DOI to BibTeX: what the tool outputs and how to use it in LaTeX

The BibTeX panel emits an @article entry by default for any CrossRef record whose type is journal-article. For the rare cases where CrossRef returns a different type (book chapter, conference paper, preprint), the panel switches to @incollection, @inproceedings, or @misc as appropriate. The cite key follows the convention firstauthorlower-year-firsttitlewordlower (e.g. hardin1968tragedy) with non-ASCII characters folded down. Change it to whatever your .bib file already uses before you paste; the panel is editable in place.

Drop the entry into your project’s .bib file, run bibtex or biber, and \cite{hardin1968tragedy} resolves in your manuscript. Overleaf, Pandoc, and every modern LaTeX distribution handle this identically. If you maintain a single shared .bib across a thesis, point this tool at each new DOI as you find it and append the entries; deduplication can wait until the bibliography compile step.

When CrossRef’s metadata is wrong (and how to fix the output)

The formatter is deterministic. Whatever CrossRef stored is what comes out. CrossRef stores what publishers deposit, and publishers vary. Three failure modes account for the bulk of bad output:

Missing or incorrect author initials. A paper credited on the PDF to Doe, J. A. may appear in CrossRef as Doe, J. because the publisher’s deposit script dropped middle initials. Fix in the output panel directly, using the PDF as ground truth. The “Source: CrossRef” link beneath each panel opens the raw record so you can confirm what was deposited.

Title capitalisation problems. Some publishers deposit titles in ALL CAPS, others in all lowercase, others in a mix. APA wants sentence case, MLA and Chicago want title case. The formatter respects whatever CrossRef stored, which means a paper deposited as “the tragedy of the commons” will appear lowercase in the output. Edit the panel before copying.

Missing month, issue, or page range. Common for online-first articles that have not been assigned to a print issue, and for older articles where the deposit predates field-level metadata. The output renders the affected field empty or substitutes n.d. Look up the missing field on the publisher’s article page and patch the output.

A reasonable habit when copying high-stakes citations (a dissertation, a grant submission, a journal resubmission): open the CrossRef record, scan the JSON for the fields you care about, fix the panel if anything looks off, then copy.

When to use this tool vs a reference manager

Use this tool when: one paper, right now, into an email, draft, or message. Or: switching a manuscript’s reference style for a resubmission and you already have the DOIs lined up.

Use Zotero, Mendeley, EndNote, or Paperpile when: you are building a bibliography of more than a dozen papers, sharing references with co-authors, attaching PDFs to records, or syncing across devices.

Use Fynman when: the literature review itself is the work. Fynman screens, extracts, and synthesises across hundreds of papers in one project, and pulls every cited reference out as a structured record. The DOI converter on this page is for one-off citations. The screening side of a full review is covered in our literature review strategies guide.

Key data we used to build this

DOI extraction regex. The official DOI Handbook (section 2.2) defines the prefix as 10.\d{4,9} and the suffix as case-insensitive alphanumeric plus -._;()/:. The tool uses exactly that pattern, applied case-insensitively to the input text, so any wrapping context is stripped off cleanly.

CrossRef coverage. As of 2026, CrossRef indexes roughly 155 million records and covers approximately 92% of journal articles published since 2000. Coverage for books and dissertations is weaker; the tool surfaces a warning when CrossRef returns a sparse record.

CSL style versions. APA 7th edition (2020), MLA 9th edition (2021), Chicago Manual of Style 17th edition author-date system (2017). The formatters target these specific versions; older variants are not supported.

Cite-key heuristic. firstauthorlastnamelower + year + firstsignificanttitleword, ASCII-folded, with stop words (the, a, an, of, on, in) skipped over. Designed to produce keys that read naturally and rarely collide. Editable per entry.