How to use: ISBN Validator
ISBN Validator is a free online Validators & Checksums tool that check ISBN-10 and ISBN-13 check digits and compute the correct one for a truncated ISBN instantly in your browser. Paste your data, adjust the options and get the result in real time — no installation, no sign-up, and nothing is ever uploaded to a server.
Description
Check ISBN-10 and ISBN-13 check digits and compute the correct one for a truncated ISBN.
- Validators & Checksums
- Because everything is computed client-side, ISBN Validator is safe to use with sensitive data such as API keys, tokens or private logs.
How to use
Using ISBN Validator takes three steps:
- Paste your data into the input box (or load the example).
- Configure the options to match your target format or scenario.
- Copy, download or inspect the output — it updates live as you type.
Run
Examples
A valid ISBN-13; the tool also accepts 10-digit ISBNs where the check digit may be X.
Input
978-0-306-40615-7
Output
ISBN-13 978-0-3064061-5-7 Prefix: 978 (Bookland / EAN-13 book) Weighted sum: 100 → 0 ✓ VALID Algorithm: alternate weights 1 and 3 from the left; total must be a multiple of 10.
This output was produced by actually running the tool, not written by hand.
Use cases
Common situations where ISBN Validator helps:
- Check ISBN-10 and ISBN-13 check digits and compute the correct one for a truncated ISBN.
Parameters
This tool has no options — it works on the input alone.
FAQ
What is ISBN Validator?
ISBN Validator check ISBN-10 and ISBN-13 check digits and compute the correct one for a truncated ISBN. It runs entirely in your browser, so your data stays private.
Is ISBN Validator free to use?
Yes. ISBN Validator is free, unlimited and works without registration or installation.
Does my data get uploaded?
No. All processing happens locally in your browser; nothing is sent to any server.
Good to know
- Everything runs client-side, so extremely large inputs are limited by your browser tab’s memory rather than by a server upload limit.