ISBN Validator
Paste an ISBN to check whether it is valid — complete with the reason if it is invalid and a component breakdown if it is valid. Everything is processed on your device.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
978-3-16-148410-0
Example Output
✓ VALID — ISBN-13, prefix 978
How to Use
- 1Paste the an ISBN you want to check into the input box.
- 2If the tool offers extra options (e.g. dialect, flags, or variant), set them as needed.
- 3Click Validate (or press Ctrl+Enter).
- 4Read the result badge — VALID, INVALID, or VALID with a warning — along with the details and the list of issues, if any.
About ISBN Validator
ISBN Validator detects and validates both ISBN-10 and ISBN-13 automatically. ISBN-10 uses a mod-11 checksum (with X as value 10), while ISBN-13 uses a 1-3 weighted mod-10 checksum (same as EAN-13). Spaces and hyphens are ignored.
Useful for validating book-catalog data, metadata imports, or store entries before saving.
FAQ
Is my data sent to a server?
No. All validation runs in your browser with JavaScript. Nothing is uploaded, logged, or stored on our servers — safe for sensitive data.
How is this validator different from a parser or formatter?
A validator answers one question: is this input correct/valid? It returns a valid/invalid badge with the reason. A parser breaks input into its components, and a formatter tidies its layout. Use a validator when you just need to confirm something is sound before using it.