How to use: Mod-11 Check Digit Validator
Mod-11 Check Digit Validator is a free online Validators & Checksums tool that validate ISSN, ISMN, ORCID and other mod-11 identifiers, with the weighted sum shown 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.
Use Mod-11 Check Digit Validator now →
Description
Validate ISSN, ISMN, ORCID and other mod-11 identifiers, with the weighted sum shown.
- Validators & Checksums
- Because everything is computed client-side, Mod-11 Check Digit Validator is safe to use with sensitive data such as API keys, tokens or private logs.
How to use
Using Mod-11 Check Digit 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
The payload of an ISSN; the tool computes the mod-11 check character.
Input
03785911
Output
529018761 Weights n…2 sum: 156 156 mod 11 = 2 Expected check character: 9 Actual: 1 Result: ✗ INVALID Used by ISSN, ISMN, ORCID (mod 11-2) and ISBN-10.
This output was produced by actually running the tool, not written by hand.
Use cases
Common situations where Mod-11 Check Digit Validator helps:
- Validate ISSN, ISMN, ORCID and other mod-11 identifiers, with the weighted sum shown.
Parameters
This tool has no options — it works on the input alone.
FAQ
What is Mod-11 Check Digit Validator?
Mod-11 Check Digit Validator validate ISSN, ISMN, ORCID and other mod-11 identifiers, with the weighted sum shown. It runs entirely in your browser, so your data stays private.
Is Mod-11 Check Digit Validator free to use?
Yes. Mod-11 Check Digit 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.