Valid ISBN-13 Generator
Generate a random ISBN-13 number with a correctly calculated check digit — useful for populating a test database or a book catalog mockup.
How it works
The ISBN-13 is a unique code assigned to every published book. Its first 12 digits always start with 978 or 979, and the 13th is a check digit calculated with alternating weights (1 and 3), which allows automatic detection of input errors.
Does this ISBN correspond to a real book?
No, this is a randomly generated but structurally valid number, useful for testing or mock data — it is not registered with any publisher.
What is the difference between the 978 and 979 prefixes?
Both are official prefixes of the ISBN system; 978 was the first one used, and 979 was introduced later to extend the available numbering space.
Generation happens entirely in your browser via WebAssembly, with no data sent to a server.