ISBN Validator
Check whether a book’s ISBN-10 or ISBN-13 is valid using its check digit. Hyphens and spaces are ignored.
How it works
- 1
Type or paste the ISBN
With or without hyphens.
- 2
See if it is valid
The check digit is verified.
- 3
Read the format
ISBN-10 or ISBN-13 is detected by length.
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Frequently asked questions
ISBN-13 replaced ISBN-10 in 2007 and is compatible with EAN barcodes.
How ISBN check digits work
The last digit of an ISBN is a check digit that catches typing errors. ISBN-10 uses a weighted sum divided by 11 (the last digit can be X for 10), while ISBN-13 uses alternating weights of 1 and 3 divided by 10.
A valid result means the number is well-formed. It does not confirm that a book with that ISBN was ever published.