Validate ISBN book numbers - ISBN-10/13 validation, check digit calculation, format conversion
ISBN (International Standard Book Number) is a unique identifier for books. ISBN-10 is 10 digits (used before 2007), ISBN-13 is 13 digits (current standard). The last digit is a check digit for validation.
ISBN-10 uses mod-11 check algorithm, check digit can be 0-9 or X (representing 10). ISBN-13 uses mod-10 check algorithm (same as EAN), check digit is 0-9. ISBN-13 starts with 978 or 979.
ISBN-10: Multiply each digit by position weight (10 to 1), sum mod 11, subtract from 11. ISBN-13: Odd positions Γ1, even positions Γ3, sum mod 10, subtract from 10 (if remainder is 0, check digit is 0).
Possible reasons: 1) Input error (wrong or missing digits); 2) Incorrect check digit; 3) Invalid ISBN format; 4) Fabricated ISBN. It doesn't mean the book doesn't exist, just the number is invalid.
This tool only validates ISBN format and check digit. For book details (title, author, publisher), use Open Library API (https://openlibrary.org/isbn/ISBN) or Google Books API.
ISBN (International Standard Book Number) is a unique identifier for books. ISBN-10 is 10 digits (used before 2007), ISBN-13 is 13 digits (current standard). The last digit is a check digit for validation.
ISBN-10 uses mod-11 check algorithm, check digit can be 0-9 or X (representing 10). ISBN-13 uses mod-10 check algorithm (same as EAN), check digit is 0-9. ISBN-13 starts with 978 or 979.
ISBN-10: Multiply each digit by position weight (10 to 1), sum mod 11, subtract from 11. ISBN-13: Odd positions Γ1, even positions Γ3, sum mod 10, subtract from 10 (if remainder is 0, check digit is 0).
Possible reasons:
1) Input error (wrong or missing digits);
2) Incorrect check digit;
3) Invalid ISBN format;
4) Fabricated ISBN. It doesn't mean the book doesn't exist, just the number is invalid.
This tool only validates ISBN format and check digit. For book details (title, author, publisher), use Open Library API (https://openlibrary.org/isbn/ISBN) or Google Books API.