Is my input uploaded?

No. This website tool runs in your browser. Only the optional public API version sends input to the authenticated API route.

Can I use this in an application?

Yes. The Developers documentation lists the authenticated endpoint, request parameters and response example.

Should I verify the result?

Yes. Deterministic tools are designed for repeatable results, but format-specific or heuristic output should still be checked for your use case.

Student & Education

ISBN Validator

Normalize and verify the checksum of ISBN-10 and ISBN-13 book identifiers.

Free foreverRuns in your browserNo sign-up

ISBN-10 or ISBN-13

Result

Enter your values and select validate isbn.

About the ISBN Validator

ISBN Validator is a focused browser-based utility. Normalize and verify the checksum of ISBN-10 and ISBN-13 book identifiers.

The calculation runs locally in your browser, so the supplied value is not uploaded to ToolsOnDuty. The same capability is also available through the authenticated developer API.

Key features

Fast local processing with explicit validation
Copy-ready structured result
No account, upload or paid data provider required

How to use

1Enter an ISBN-10 or ISBN-13.
2Choose any available conversion or formatting options.
3Run the tool and review the normalized identifier, format and validity.

Examples

ISBN Validator example

Input: an ISBN-10 or ISBN-13

Output: the normalized identifier, format and validity

Frequently asked questions

Is my input uploaded?: No. This website tool runs in your browser. Only the optional public API version sends input to the authenticated API route.
Can I use this in an application?: Yes. The Developers documentation lists the authenticated endpoint, request parameters and response example.
Should I verify the result?: Yes. Deterministic tools are designed for repeatable results, but format-specific or heuristic output should still be checked for your use case.