ISBNConverter.com was built to solve a problem that anyone working with book data knows intimately: ISBN formats don't agree with each other, and correcting that takes time nobody has.
Publishers maintaining catalogues across multiple platforms need ISBN-10 for legacy systems and ISBN-13 for everything current. Librarians reconciling records between databases like WorldCat encounter both formats daily. Booksellers exporting inventory to Amazon, Ingram, or Baker & Taylor need a specific format that may differ from what their system stores. Developers building cataloguing tools, e-commerce platforms, or publisher integrations need to convert ISBNs in real time without implementing checksum logic themselves.
ISBNConverter.com handles all of it: no registration required, no data reformatting needed, and no uploading your catalogue to a service you don't control.
What ISBNConverter.com does
Three tools cover the full range of ISBN conversion workflows:
The single converter converts one ISBN at a time. Enter an ISBN-10, ISBN-13, EAN-13, or UPC-A and get all applicable equivalents instantly. Use it for individual lookups, one-off verifications, and checking a specific code.
The bulk converter accepts any number of ISBNs pasted in any format: comma-separated, space-separated, one per line, or mixed into other text. Non-ISBN text is left exactly as entered, so you can paste a raw catalogue export without preprocessing. Use it for converting a list copied from a spreadsheet or CMS.
The file upload converter takes an Excel (.xlsx), CSV, TSV, or plain text file and delivers a converted copy as a download. It supports five column placement options: placing converted ISBNs before, after, at the start, at the end of each row, or replacing the original in place. Use it for structured data workflows where the output needs to go back into a file.
For automated pipelines, the REST API converts any ISBN format via a simple GET request authenticated with an API key header.
Supported formats
- ISBN-10: 10-digit format used for books published before 2007; still common in legacy systems and many publisher databases.
- ISBN-13: Current standard since 2007; technically identical to EAN-13 with a "978" or "979" prefix.
- EAN-13: The barcode standard used in global retail, of which ISBN-13 is a subset.
- UPC-A: 12-digit format used primarily in North America; convertible to EAN-13 by prepending a leading zero.
Note: ISBN-13 codes with a "979" prefix have no ISBN-10 equivalent. The ISBN-10 address space only covers the "978" namespace. These codes are returned unchanged.
Why ISBNConverter.com exists
Most existing ISBN conversion tools are slow, ad-heavy, limit how many codes you can convert, or sit behind registration walls. ISBNConverter.com is fast, free for reasonable use, and designed to handle data as it actually arrives: messy formats, mixed content, quoted codes, and all. Free accounts get 100 conversions per month at no cost. Paid credits extend that limit with no subscription and no expiry.
Get in touch
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