Amazon · Identifier
ASIN format validator.
Paste one or many ASINs. The tool checks length and characters, tells you whether each looks like a B0 product code or a book-style number, and tests the ISBN-10 checksum where it applies.
Inputs
Result
Enter an ASIN and press Check.
What an ASIN is, and what can be checked
Amazon describes an ASIN as a unique 10-character alphanumeric code assigned to every product in its store. It says the format “typically starts with B0, or in the case of books begins with a number”, with examples B07FZ8S74R and 0451524934. That is all this tool treats as the rule: exactly 10 letters and digits.
We found no published check-digit scheme for ASINs, so there is nothing to validate beyond that shape. A well-formed ASIN can still be one that does not exist, was retired, or belongs to a different Amazon marketplace.
The ISBN-10 relationship
The book example above, 0451524934, is also a valid ISBN-10. An ISBN-10 is nine digits plus a check character (0 to 9 or X); multiply the ten characters by weights 10 down to 1 (X counts as 10) and the total must divide by 11. When a numeric ASIN passes that test, the tool shows the matching ISBN-13 (978 + the first nine digits + a GS1 mod-10 check digit). We treat a passing result as “consistent with an ISBN-10”, not as proof that Amazon uses that ISBN for the listing. Also see the ISBN barcode generator.
Sources retrieved October 2026. Amazon: What is an ASIN? (10-character alphanumeric code; B0 prefix; books begin with a number); ISBN-10 weighting is the method defined for ISBN-10 in ISO 2108 (see ISBN International); ISBN-13 check digit per GS1: how to calculate a check digit manually.
Frequently asked questions
How do I know if an ASIN is valid?
Format-wise it is exactly 10 letters and digits. Whether it is live on a given Amazon store can only be confirmed on Amazon itself; this tool does not contact Amazon.
Is an ASIN the same as a UPC or GTIN?
No. An ASIN is Amazon’s own catalogue number. A UPC, EAN or GTIN is a GS1 number printed on the product. The two are different identifiers.
Why does my numeric ASIN fail the ISBN-10 check?
Either it was mistyped or it is not an ISBN-10. A passing checksum only means it is consistent with one.
Are ASINs the same in every country?
Not necessarily. Check the product page of each marketplace you sell in.
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