free · in-browser · no upload
Drop your NBIB file. We'll convert it to CSL-JSON right here in your browser, your file never leaves your device.
Select your file here to get started
or drop your file here.
Accepts .nbib
How it works
Click the dropzone above or drag a NBIB from your desktop. Files of any size, there's no upload, so there's no upload limit.
The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.
Get your CSL-JSON the moment the conversion finishes. Convert another, or close the tab.
Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.
Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.
No account required. No watermark on the output. No queue. Drop a file, get a converted file.
Why convert NBIB → CSL-JSON
NBIB is PubMed's MEDLINE/NBIB export; CSL-JSON is the Citation Style Language JSON that Zotero, pandoc, and citeproc speak. This converts one to the other through a shared bibliographic model, so every field that round-trips (title, authors, year, journal, volume, pages, DOI) carries across without re-keying. Runs entirely in your browser, no upload.
You have a PubMed export (Send to → Citation manager) and your next tool wants CSL-JSON. Drop the file here and get a clean CSL-JSON file back in one step.
Some references are missing fields after conversion.
Fields only carry across if the source NBIB actually contained them. Open the source and confirm the field is populated; CSL-JSON cannot add data that was not there.
Formats involved
NBIB is the National Library of Medicine's citation format for PubMed exports. Structurally identical to RIS with a different tag dictionary (PMID, FAU, JT, AID instead of ID, AU, JO, DO). Reference managers treat .nbib files as RIS-flavored with PubMed-specific extensions. The format ships with PubMed downloads and the major systematic-review tools (Covidence, Rayyan).
How to open
Zotero, Mendeley, EndNote, Papers, all read NBIB natively. Plain text in any editor.
CSL-JSON is the modern interop format for citation metadata. Zotero exports it natively (right-click a collection → Export → CSL JSON). Pandoc consumes it as `--bibliography file.json` for reference rendering. Every major reference manager (Zotero, Mendeley, Citavi, Papers, Bookends) reads or writes it. Defined by the Citation Style Language project; covers ~100 fields across journals, books, chapters, theses, software, datasets, and more. The de-facto replacement for BibTeX in modern academic toolchains.
How to open
Any JSON viewer or text editor. Zotero imports via File → Import → CSL JSON. Pandoc references it as bibliography input. JabRef, Citavi, and Bookends all accept CSL-JSON drop-ins.
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FAQ
Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.
Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.
Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.
PubMed citation export; systematic review imports. Cross-tool bibliography exchange between reference managers. The most common reason to convert is compatibility, CSL-JSON works in places where NBIB doesn't, or vice versa.
Zotero, Mendeley, EndNote, Papers, all read NBIB natively. Plain text in any editor.
Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.
Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.
