twineconvert

free · in-browser · no upload

MARCXML to NBIB
Converter

Drop your MARCXML file. We'll convert it to NBIB right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .xml, .marcxml, .mrcx

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a MARCXML from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your NBIB the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

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.

No file size limit

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.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert MARCXML → NBIB

What this conversion is actually for

MARCXML is MARC21 catalog records in XML, the format library systems (Koha, Alma, Sierra) and the Library of Congress export. This converts a MARCXML record to NBIB so you can reuse the bibliographic data in a PubMed-style manager. Title (245), authors (100/700), year, host journal (773), volume, issue, pages, DOI (024), ISSN (022), and ISBN (020) are extracted. Runs in your browser, nothing is uploaded.

A real example

You exported records from your library catalog as MARCXML and need them in NBIB for a PubMed-style manager. Drop the .xml here and get NBIB back.

Troubleshooting

The DOI or year is missing.

DOIs must be in an 024 field with first indicator 7 and a $2 of doi. For journal articles the year is read from the 773 host-item string; records without a 773 fall back to the 260/264 publication date.

Formats involved

About MARCXML and NBIB

MARCXML, MARCXML

MARCXML is a file format we support converting. Detailed format information is being added, for now, drop your file in the converter above and you'll get the conversion you came for.

How to open

Most operating systems open this format with a default application; if not, search for a free reader/viewer for the format.

NBIB, PubMed citation format

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.

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FAQ

Common questions

Is this MARCXML → NBIB converter really free?

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.

Where does my file go when I convert it?

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.

What's the maximum file size?

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.

Why convert MARCXML to NBIB?

File interchange. PubMed citation export; systematic review imports. The most common reason to convert is compatibility, NBIB works in places where MARCXML doesn't, or vice versa.

How do I open a MARCXML file in the first place?

Most operating systems open this format with a default application; if not, search for a free reader/viewer for the format.

Does this work offline?

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.

Can I convert multiple files at once?

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.