Are the ISBNs generated here officially assigned?

No. These are mathematically valid ISBN-13 numbers (correct check digit) but they are not registered with any ISBN agency. Do not use them to publish real books.

How is the ISBN-13 check digit calculated?

Multiply each of the first 12 digits alternately by 1 and 3, sum the results, then subtract (sum mod 10) from 10. If the result is 10, the check digit is 0.

Can I generate ISBN-10 numbers?

ISBN-10 only applies to the 978 prefix. Enable the "Show ISBN-10" toggle and the tool will display the ISBN-10 equivalent alongside each ISBN-13.

What is the difference between the 978 and 979 prefixes?

978 is the original GS1 prefix ("Bookland") used since ISBN-13 was introduced. 979 is a newer prefix used when the 978 space runs low; 979 ISBNs have no ISBN-10 equivalent.

What does the publisher prefix field do?

You can optionally lock the first few digits after the GS1 prefix to simulate a specific publisher or country group. Leave it blank for fully random generation.

ISBN-13 Generator

Name: ISBN-13 Generator
Availability: InStock
Author: Nham Vu

Generate valid ISBN-13 (and ISBN-10) numbers with correct check digits for books, testing, and publishing workflows.

ISBN Options

GS1 Prefix

Publisher Prefix (optional, digits only)

Up to 7 digits after the GS1 prefix (total 12 digits before check).

Quantity — 10

Show ISBN-10

Generated ISBNs

No ISBNs generated yet

Configure options on the left and click Generate.

How the check digit is calculated

Generate an ISBN above to see the step-by-step check digit calculation.

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Summary

Generate valid ISBN-13 (and ISBN-10) numbers with correct check digits for books, testing, and publishing workflows.

How it works

Choose the ISBN-13 prefix (978 or 979) and optionally enter a publisher/group prefix.
Set how many ISBNs to generate (1–100).
Click "Generate" to produce a list of valid ISBN-13 numbers.
The tool fills in a random title number and calculates the GS1 check digit automatically.
Enable "Show ISBN-10" to see the equivalent ISBN-10 for 978-prefix numbers.
Copy individual ISBNs or export the full list as plain text.

Use cases

Generate placeholder ISBNs for software testing and QA.
Create sample book records for database seeding.
Validate your own ISBN-13 check digit implementation.
Produce dummy catalog entries for publishing system demos.
Understand the ISBN-13 check digit algorithm interactively.
Convert between ISBN-13 (978-prefix) and ISBN-10 formats.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu