Simply reload your original BibTeX files and select a different duplicate strategy. The tool never alters your local files, so you can regenerate any merge variant instantly.

Does it support large BibTeX exports?

Yes. The browser-based parser works efficiently with very large bibliographies, especially when you merge in batches and use the compact spacing option for lighter output.

How are duplicate keys detected?

Keys are matched in a case-insensitive way. When conflicts arise you can keep the first entry, keep the most recent upload, or blend distinct fields into a single enriched citation.

What makes the duplicate CSV report special?

Beyond merging, the tool can export a CSV intelligence report that lists every conflicting key, its entry type, and source files, helping teams resolve issues faster than competing solutions.

Merge BibTeX Files Online | Lightning-Fast Deduplicator

Upload & Merge

Add your BibTeX files

Add unlimited .bib files. We never upload anything — all processing happens in your browser.

Drag & drop BibTeX files here

Smart Merge Settings

Duplicate Resolution When keys collide Blended merge keeps the widest field coverage while avoiding duplicates — ideal for collaborative libraries.

Ordering Sort merged entries by

Whitespace Compact spacing

Preview Filter entries Instantly filter the preview and duplicate report without reprocessing.

Merged Bibliography

Merged BibTeX output

Duplicate Intelligence

Entries listed below share the same citation key. Use the filter above to isolate specific citations.

Duplicate BibTeX citation keys summary
Citation Key	Type	Occurrences	Sources

Merge BibTeX Resource Guide

About This BibTeX Merger

Merge BibTeX Files Online is engineered for researchers, librarians, and academic teams who need a quick way to consolidate citation libraries without sending sensitive data to external servers. The tool loads instantly, can be saved for offline use, and handles large bibliographies while keeping every operation inside your browser. Compared with traditional command-line scripts or bulky desktop clients, you get a cleaner interface, smarter duplicate handling, and crystal-clear exports that are ready for LaTeX, Overleaf, or reference managers.

How to Use the Merger

Select or drag multiple .bib files into the upload panel. Review the file badges to confirm the order of priority, then pick a duplicate resolution strategy that matches your workflow. The Keep First option respects the earliest file, Keep Last favors the most recent upload, and Blend Unique Fields combines non-conflicting metadata — a lifesaver when co-authors annotate entries differently. Click Merge Now to generate the consolidated bibliography, monitor the live metrics above, and download the refreshed .bib archive in one click.

Productivity Tips

Use the preview filter to rapidly audit specific citation keys or authors before exporting. Toggle compact spacing when you want minimal file size, especially for repository commits. The duplicate intelligence table highlights potential conflicts instantly, and the exportable CSV report is perfect for tracking which teammate owns a conflicting entry. Because everything runs client-side, you can bookmark the page, cache it for offline reviewing, and share the clean output without worrying about privacy breaches or throttled upload limits.

FAQs

Can I undo a merge? Re-run the tool with your original files and choose a different duplicate strategy; no original files are modified. Does it support really large .bib exports? Modern browsers comfortably handle several tens of thousands of lines thanks to streaming file reads, though you can merge in batches for extra safety. What if keys differ only by case? Duplicate detection is case-insensitive to prevent accidental collisions when collaborating across systems. Is the CSV report unique? Yes — it is designed to give you immediate accountability for duplicate sources, a feature rarely seen in competing web mergers.

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