ISBN Validator
Checks whether an ISBN-10 or ISBN-13 is structurally valid.
Lilu Baba's ISBN Validator checks both ISBN-10 and ISBN-13 formats against their official check-digit formulas.
How to use this tool
- Enter an ISBN-10 or ISBN-13, with or without hyphens.
- Its validity updates instantly based on the official check-digit algorithm.
FAQ
ISBN Validator — frequently asked questions
The final digit of an ISBN, calculated from the preceding digits, used to catch typos and transcription errors.
No — this only checks that the ISBN is structurally valid, not whether it corresponds to a real published book.