NBIB Converter
Paste or upload the .nbib file PubMed gives you and convert it to RIS, BibTeX or CSL JSON. Authors are read in full where PubMed has them, abbreviated page ranges such as 16569-72 are expanded, MeSH terms become keywords, and retracted publications are flagged. Everything runs in your browser; nothing is uploaded. Free, no sign-up.
Paste the text or upload the file from PubMed's Save → Citation manager (.nbib) or its MEDLINE format. It is converted in your browser — nothing is uploaded.
Paste or upload a PubMed .nbib file to convert it.
How to Use the NBIB Converter
- 1. Get the file from PubMed. Run your search, choose Send to → Citation manager, pick the results (all, this page or a selection) and download the .nbib file. Saving in PubMed's “PubMed” format produces the same tags.
- 2. Add it here. Upload the file or paste its text. A file that is not valid UTF-8 is read as Windows-1252 and the page tells you.
- 3. Choose the format. RIS for Zotero, Mendeley, EndNote and screening tools; BibTeX for LaTeX; CSL JSON for Pandoc and Zotero.
- 4. Check the warnings and download. Retractions, missing titles and unreadable dates are listed by record.
Why Convert an NBIB File
Many tools read .nbib directly, but not all of them read it well, and some read only RIS. Systematic-review screening tools, institutional repositories and older reference managers are common cases. BibTeX users need a different file altogether. Converting gives you one clean file in the format your tool prefers, and shows you what PubMed's tagged lines turned into before you import them. If you only have PMIDs, the PubMed to BibTeX Converter tool looks them up; this one converts a file you already have, without a lookup.
How PubMed Tags Map
| PubMed tag | RIS tag | Notes |
|---|---|---|
| PMID | AN, DB and UR | Accession number, database “PubMed” and the record's PubMed link. |
| TI | TI | PubMed's closing full stop is dropped. |
| FAU, or AU when there is no FAU | AU, one per person | Full names are used where PubMed has them; “Smith JA” becomes Smith, J. A. |
| CN | AU | A collective (group) author is written as one name. |
| JT and TA | T2 and J2 | Journal title and NLM abbreviation. |
| VI, IP, PG | VL, IS, SP and EP | An abbreviated page range is expanded. |
| DP, then DEP | PY and DA | DP is the publication date; DEP (the electronic date) is used only when DP is missing. |
| AID or LID tagged [doi] | DO | Other identifiers such as [pii] are ignored. |
| IS | SN | The first ISSN, without its “(Print)” or “(Electronic)” note. |
| AB | AB | The abstract, wrapped lines joined. |
| MH and OT | KW | MeSH terms and author keywords; the asterisk that marks a major topic is removed. |
| PT and PMC | N1 | Publication types and the PubMed Central ID, kept as notes. |
Details That Trip Up Other Converters
- Abbreviated page ranges. PubMed writes 16569-72 for pages 16569 to 16572. Left alone, a reference manager reads page 72 as the last page. The converter fills in the leading digits.
- Initials without full stops. PubMed writes “Hirsch, J E”; reference managers and style files expect J. E., so the converter adds the stops.
- Wrapped lines. A long title or abstract continues on lines indented by six spaces; they are joined with a single space.
- Repeated tags. Records carry several PT, MH, AU and LID lines. Each is read in order, and the DOI is taken from the LID or AID line marked [doi].
A Worked Example
The sample button loads two PubMed records. The second is Hirsch's 2005 h-index paper. PubMed has pages as 16569-72 and the author as “Hirsch, J E”, and the RIS comes out as:
The second sample record as RIS
TY - JOUR AU - Hirsch, J. E. TI - An index to quantify an individual's scientific research output T2 - Proceedings of the National Academy of Sciences of the United States of America J2 - Proc Natl Acad Sci U S A PY - 2005 DA - 2005/11/15/ VL - 102 IS - 46 SP - 16569 EP - 16572 SN - 0027-8424 DO - 10.1073/pnas.0507655102 UR - https://pubmed.ncbi.nlm.nih.gov/16275915/ LA - eng AN - 16275915 DB - PubMed AB - I propose the index h, defined as the number of papers with citation number > or =h, as a useful index to characterize the scientific output of a researcher. N1 - Publication types: Journal Article ER -
What the Warnings Mean
- Retracted publication — PubMed's publication-type list marks the record as retracted. Do not cite it as sound evidence; check the retraction notice, and note it in your screening log if you are doing a review.
- Retraction notice — the record is the notice itself, not the article it retracts.
- No title or no authors — converted as it is. Missing authors are normal for some editorials and news items.
- Date with no year — PubMed's date field held something the converter could not read, so the date is left out rather than guessed.
What Is Sent, and Where
Nothing. The file is read and converted by code running in your browser; no part of it goes to CitationEasy or any other service, and nothing is kept after you close the page.
Frequently Asked Questions
- What is an NBIB file?
- An .nbib file is the citation-manager export from PubMed. It is plain text in the MEDLINE tagged format, with one record per reference, tags such as PMID, TI, FAU and AB, and a blank line between records.
- How do I download an NBIB file from PubMed?
- Search PubMed, choose Send to above the results, select Citation manager, then choose all results, the results on this page or your selection and click Create file. PubMed caps how many records one file can hold, so split a very large search by year or topic.
- How do I convert NBIB to RIS?
- Upload or paste the file here and keep RIS selected, then download the .ris file. Import it into Zotero, Mendeley, EndNote, or a screening tool such as Rayyan or Covidence.
- How do I convert NBIB to BibTeX?
- Choose BibTeX instead. Citation keys are built from the first author, year and first significant title word, and made unique with a, b, c suffixes where they repeat. The MeSH terms and abstract are not part of the BibTeX output; use RIS or CSL JSON to keep them.
- Are MeSH terms kept?
- Yes, in RIS and CSL JSON, as keywords. The asterisks that mark major topics are removed, and subheadings stay attached, as in “Publishing/trends”. The MeSH Term Finder explains how to read them.
- Why does PubMed abbreviate page numbers?
- NLM's convention writes the second number of a range with only its differing digits, so 16569-72 means 16569–16572. Many import tools do not expand it, which is why the converter does.
- Is my file uploaded anywhere?
- No. The conversion runs entirely in your browser, and nothing is sent to a server.