Free tool

BibTeX validator

Paste your .bib file and catch problems before they render as[?] in your PDF. Runs entirely in your browser; nothing is uploaded.

BibTeX input0 entries
Validation results

Paste your .bib file to validate it instantly.

Reference

BibTeX entry types and their fields

The validator checks each entry against the classic BibTeX contract. Required fields must be present; optional fields are fine either way.

Entry typeRequired fieldsOptional fields
@articleauthor, title, journal, yearvolume, number, pages, month, doi, url
@booktitle, publisher, year, author or editorvolume, series, edition, address, isbn, doi
@inproceedingsauthor, title, booktitle, yearpages, address, publisher, doi
@conferenceauthor, title, booktitle, yearpages, address, publisher
@phdthesisauthor, title, school, yearaddress, month, type, doi
@mastersthesisauthor, title, school, yearaddress, month, type
@techreportauthor, title, institution, yeartype, number, address, month
@miscnoneauthor, title, year, url, note, howpublished
@unpublishedauthor, title, noteyear, month
@proceedingstitle, yeareditor, publisher, address, volume
@manualtitleauthor, organization, year, edition
@incollectionauthor, title, booktitle, publisher, yeareditor, chapter, pages, address

In the Oleafly desktop app, this validation runs continuously against your project, and Add citation can fetch a correct entry from a DOI, arXiv id, or title so you never hand-type one again.