Type the code
With or without hyphens: ISBN, EAN or UPC.
ISBN and EAN validator
Type a book or product code and see whether its check digit is right. Convert between ISBN-10 and ISBN-13, or complete a code that is missing its last digit.
- Free
- No sign-up
- Runs in your browser
100% private — the calculation is done in your browser and nothing is sent to any server.
How it works
Read the check
Valid or not, and what the check digit should be.
Convert if you need to
ISBN-10 to ISBN-13, and back for books with a 978 prefix.
The number on the back of the book
Every book has an ISBN, the International Standard Book Number, and every product on a shop shelf has a barcode number: EAN in most of the world, UPC in North America. They look like plain numbers but their last digit is a check digit calculated from the others, so that a mistyped number can be detected. Libraries, bookshops, online stores and inventory systems all rely on it. This tool verifies it and converts between the two ISBN forms.
ISBN-10 and ISBN-13
Until 2007, ISBNs had ten characters. Since then, they have thirteen digits and are the same as the EAN-13 barcode of the book, with a prefix of 978 or 979. An ISBN-10 can be converted into an ISBN-13 by adding 978 in front and recalculating the last digit, and a 978 ISBN-13 can be converted back to an ISBN-10. The two forms identify the same edition. The ISBN-10 check character can be an X, which stands for ten.
EAN and UPC
EAN-13 is the thirteen-digit barcode used in Europe and most of the world, EAN-8 is a short form for small packages, and UPC-A is the twelve-digit code used in the United States and Canada. GTIN-14 is used for cartons. All of them use the same weighted check digit, and the tool validates each by its length.
Missing the last digit?
If you enter nine digits, the tool works out the ISBN-10 check character and gives you the complete number. That is useful when a source lists the number without it.
What it does not do
A correct check digit shows the number is well formed, not that a book or product with that code exists. The tool does not look up titles, publishers or prices, and it does not tell you the country of a barcode. To print a barcode from a code, use the barcode generator.
Frequently asked questions
How do I check an ISBN?
Type the ISBN with or without hyphens. The tool checks the last digit and tells you whether the number is valid.
How do I convert an ISBN-10 to ISBN-13?
Enter the ISBN-10. The ISBN-13 appears with the 978 prefix and a recalculated check digit.
What does the X at the end of an ISBN-10 mean?
It stands for ten, the value of the check digit when it cannot be written as one digit.
Is an EAN the same as an ISBN-13?
For books, yes: an ISBN-13 is an EAN-13 with a 978 or 979 prefix.
Can it find a book from its ISBN?
No. It only checks and converts the number.
Is my data sent anywhere?
No. The calculation is done in your browser.
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