ISBN Check & Converter
Validate ISBN-10 and ISBN-13 check digits, convert between the two (978 ↔ 10; 979 stays 13-only), complete a body, and draw the EAN-13 barcode — in bulk.
Per line: valid or not with the correct check digit, the other form of the ISBN, and a scannable EAN-13 barcode SVG for the first valid ISBN-13; hyphenation left as typed, with the reason stated.
Example: ISBN 0-306-40615-2 is valid and becomes 978-0-306-40615-7; 0306406153 fails (check should be 2); 979-1-234-56789-6 has no ISBN-10 form; 0-8044-2957-X shows the X check digit.
Two check digits,
one number.
How each ISBN form is checked, how conversion works, and why hyphens are left alone.
ISBN-10 and ISBN-13
ISBN-10 weights its nine digits 10 down to 2, sums, and the check digit is what makes the total divisible by 11 — an X stands for 10. ISBN-13 is an EAN-13: 978 or 979, nine digits, and the EAN modulo-10 check. A valid ISBN-10 becomes ISBN-13 by prefixing 978 and recomputing; a 978 ISBN-13 goes back the same way, a 979 has no ISBN-10 form.
Barcode
The EAN-13 of the first valid ISBN-13 is drawn with the in-house EAN encoder — the "Bookland" barcode on a book’s back cover, minus the optional 5-digit price add-on.
Hyphens
Where the hyphens go depends on the registration group and registrant ranges that the International ISBN Agency publishes and updates; that table is not embedded, so hyphens are shown as you typed them and the check ignores them. A valid check digit does not mean the ISBN has been issued. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- ISBN Users’ Manual (International ISBN Agency): ISBN-10 modulo-11 check with X = 10, ISBN-13 as EAN-13 with 978/979 prefix and modulo-10 check; range data for hyphenation not embedded
Last reviewed 20 September 2026. How results are checked: How we verify.