Clean and validate your BibTeX file
A broken .bib file is one of the most common causes of a failed LaTeX build: a
duplicate cite key, a missing closing brace, or a missing required field can stop
the bibliography from compiling. This tool scans your BibTeX, reports every problem
it finds with the relevant cite key, and produces a cleaned, deduplicated version.
How it works
The validator parses entries with a brace-aware scanner, so nested {} inside a
field value do not confuse it. For each entry it checks four things:
- Duplicate keys — any cite key used more than once is reported; the cleaned output keeps only the first entry with that key.
- Brace balance — opening and closing braces are counted per entry and across the file; a mismatch is flagged.
- Required fields — the entry type is checked against the standard required-field list (article: author, title, journal, year; book: author/editor, title, publisher, year; inproceedings: author, title, booktitle, year; and so on).
- Non-ASCII characters — raw characters above code point 127 are flagged because classic BibTeX may not render them correctly.
Notes
The cleaned output trims trailing whitespace, collapses runs of blank lines, and removes duplicate-keyed entries, but it does not rewrite your field values — so it is safe to diff against your original. Required-field warnings are advisory: an entry with a warning still appears in the cleaned output.