Add missing DOIs to a BibTeX file

Many journals ask for a DOI on every reference, and reference managers often leave them out, especially for entries copied from Google Scholar. Finding them one by one takes minutes per reference.

BibProfile finds the missing DOIs and gives you back your .bib with them added, and nothing else changed.

See it on an example Check your own .bib

In the example, a 2012 Nature paper cited without its DOI gets it back.

How to do it with BibProfile

1. Open bibprofile.com and drop your .bib file, or paste its entries (from Overleaf: open the .bib, select all, copy). Nothing to install, no account.
2. Each reference without a DOI is matched by its title, first author and year against Crossref and OpenAlex.
3. Open the “Cleaned .bib” tab: every DOI found is listed as a change you can review, with a doi.org link to check it in one click. Download the cleaned .bib.

What gets added, and what never changes

• A DOI is added automatically only for a high-confidence match: a near-identical title, the same first author and a year within one. Any other DOI is a suggestion you accept or skip.
• Your entries are only added to. Cite keys never change, no entry is removed, a DOI you already wrote is never replaced, and everything else in the file stays exactly as it was.
• No placeholder DOIs (such as ACM’s 10.5555 or ResearchGate’s 10.13140), and a preprint’s DOI is never added to an entry for the published paper.
• Missing venues, volumes and pages can be filled too, under the same rules.

Doing it by hand

• Search the title on search.crossref.org or Google Scholar and copy the DOI.
• Open https://doi.org/ followed by the DOI to check it leads to the right paper — a DOI for the preprint or for a different paper is a common slip.
• Add it to the entry as doi = {10.xxxx/…}.

Fine for three references; tedious for thirty.

FAQ

Will it change my cite keys or reorder my file?

No. The cleaned file is your .bib with fields added: the cite keys, the order, the number of entries and every existing field stay as they were.

Why didn’t it find a DOI for every reference?

Some works have no DOI (many books, older papers, web pages and software), and some can’t be matched confidently. Those are left alone or proposed for review rather than guessed.

Does it work with Overleaf?

Yes. Paste the contents of your .bib instead of uploading a file, then download the cleaned .bib and upload it to your Overleaf project in place of the old one.

Is my .bib file uploaded anywhere?

No. The file is read in your browser and is never uploaded. To look a reference up, only its DOI, or its title, first author and year, is sent to Crossref and OpenAlex (through BibProfile’s own proxy, which keeps no record of them). There’s no account, no cookie and no tracking: BibProfile stores nothing about you or your file. Our host, Cloudflare, processes technical data such as your IP address to deliver the site (see the privacy page).

Is it free?

Yes, and there’s no account. Lookups by DOI are free; a title search on OpenAlex uses one credit from a free daily pool provided by OpenAlex and shared by everyone using BibProfile, so you never pay anything. If the pool runs out on a busy day, you can add your own free OpenAlex key or come back after the reset.

See it on an example Check your own .bib