ISBN-10 / ISBN-13 Konverter

Zwischen ISBN-10 und ISBN-13 konvertieren mit automatischer Neuberechnung der Prüfziffer und Barcode-Vorschau.

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How to Use

  1. 1
    Enter the ISBN to convert

    Type or paste the ISBN-10 or ISBN-13 value into the input field. Hyphens and spaces are ignored, so you can paste formatted values such as '978-0-306-40615-7' directly.

  2. 2
    Select the conversion direction

    The converter auto-detects the input format: 10-digit values are converted to ISBN-13 (Bookland EAN), and 13-digit values beginning with 978 are converted to ISBN-10. Note that ISBN-13s beginning with 979 have no ISBN-10 equivalent.

  3. 3
    Use the result in your catalog

    The converted ISBN is displayed with correct hyphenation based on the ISBN registration group rules. Use the ISBN-13 form when generating EAN-13 barcodes or submitting metadata to book distributors.

About

The International Standard Book Number system was created to bring unique, machine-readable identification to the global book trade. The original 9-digit SBN (Standard Book Number) was developed in the United Kingdom in 1966 by J. Whitaker & Sons. ISO adopted and extended it to 10 digits as ISO 2108 in 1970, adding a national or language-area group digit at the front. The 10-digit form served the industry for nearly four decades before capacity pressures and the need to align with the universal EAN-13 barcode system led to the transition to ISBN-13 in 2007.

The International ISBN Agency, headquartered in London, coordinates the global ISBN system through a network of 160+ national ISBN agencies. Each agency is responsible for allocating ISBNs to publishers within their jurisdiction, maintaining their national ISBN database, and ensuring that assignments are unique. Group numbers — the first hyphenated segment after the EAN prefix — are assigned by the International ISBN Agency to language regions and countries: group 0 and 1 cover English-language publishing worldwide, group 2 covers French, group 3 covers German, and so on. Publishers within each group receive a registrant prefix whose length is inversely related to their expected output volume.

For library and publishing metadata workflows, ISBN appears in multiple standards. ONIX for Books (the publishing industry's XML metadata standard) uses ISBN-13 as the primary product identifier. MARC 21, the bibliographic data format used by most library management systems, stores ISBNs in field 020 and supports both 10- and 13-digit forms. The EDItX and EDIFACT standards used in wholesale distribution similarly require ISBN-13. Developers integrating with book supply chain APIs should always normalize ISBNs to 13-digit form and store them without hyphens for reliable string comparison and database indexing.

FAQ

When and why was ISBN-13 introduced?
ISBN-13 was introduced on 1 January 2007 by the International ISBN Agency to resolve a capacity crisis in the ISBN-10 system and to align book identification with the EAN-13 barcode standard used in retail worldwide. ISBN-10 offered approximately 1 billion unique identifiers, but the rapid growth of publishing — including the emergence of e-books and print-on-demand — threatened to exhaust the supply of available numbers within certain high-output group prefixes. ISBN-13 uses the 978 (and later 979) Bookland prefixes within the GS1 EAN system, multiplying capacity and enabling book barcodes to be scanned on the same retail scanners used for any other consumer product.
Why can't I convert a 979-prefixed ISBN-13 back to ISBN-10?
ISBN-10 was defined before the 979 Bookland prefix existed, so the ISBN-10 numbering space has no equivalent for numbers that begin with 979. The International ISBN Agency introduced the 979 prefix precisely to expand beyond what the 978 prefix could accommodate. Only ISBNs in the 978 prefix range have a corresponding 10-digit form obtained by stripping the prefix and recalculating the Modulo 11 check digit. Any ISBN-13 beginning with 979-10 (France), 979-11 (Korea), 979-12 (Italy), or future group allocations under 979 must always be represented in 13-digit form.
How do ISBN hyphens work and are they mandatory?
Hyphens in an ISBN divide the number into four parts: the EAN prefix (978 or 979 for ISBN-13 only), the registration group element (country or language area), the registrant element (publisher prefix), and the publication element (title number), followed by the check digit. The hyphenation pattern is not fixed-width; it follows agency-defined range tables published by the International ISBN Agency in the Range Message XML file. Hyphens are not required for barcode encoding or machine processing, but the International ISBN Agency and major metadata standards (ONIX, MARC 21) recommend using them in human-readable displays to aid readability and error detection.
Is it valid to use an ISBN-10 on a book published after 2007?
The International ISBN Agency deprecated ISBN-10 for new assignments as of 1 January 2007. All new ISBNs issued since that date are allocated exclusively in ISBN-13 format. Publishers may still display an ISBN-10 for backward compatibility with older library and retail systems that have not migrated to 13-digit processing, but the barcode printed on the book must be an EAN-13 encoding the ISBN-13. Many publishers print both forms on the copyright page as a transitional convenience, but the ISBN-13 is the authoritative identifier.
How does the ISBN check digit differ between ISBN-10 and ISBN-13?
ISBN-10 uses a Modulo 11 algorithm where the 9 data digits are weighted from 10 down to 2, the products are summed, and the check digit is the value that brings the sum to a multiple of 11. Because this calculation can yield a remainder of 10, the character 'X' is a valid ISBN-10 check digit representing the value 10. ISBN-13 uses the same Modulo 10 algorithm as EAN-13: alternating weights of 1 and 3 are applied to the 12 data digits, and the check digit is 10 minus the sum modulo 10 (with 10 replaced by 0). The two check digits are independently calculated and will generally differ even for the same title.