Amazon Standard Identification Number (ASIN)

Format and characteristics

ASINs are typically ten characters long and can contain letters and numbers. For books that already have a 10‑digit ISBN, Amazon generally uses that ISBN as the ASIN. For other product categories, and for items without an ISBN, Amazon generates a distinct ASIN. ASINs are specific to Amazon and do not replace industry-wide identifiers such as UPC, EAN or ISBN‑13.

History and assignment

Amazon developed ASINs to organize a rapidly growing catalogue of items and to provide stable references for its pages and APIs. When a seller or publisher lists a new product, Amazon assigns an ASIN if one does not already exist for an identical item. Multiple sellers can offer the same ASIN when they sell the same product model or edition.

Uses and examples

ASINs are used for searching Amazon, generating product links (often visible after /dp/ in a URL), inventory management, advertising and by Amazon's developer interfaces. For books, the ASIN equals the ISBN‑10 when available; Kindle e‑books and older editions may receive a unique ASIN instead of an ISBN.

Distinctions and notable facts

• ASINs are Amazon‑specific and do not serve as global product identifiers.
• When an ISBN‑13 is present, it may not match the ASIN unless converted to a 10‑digit ISBN.
• Having an ASIN does not imply any external registration; it is simply an entry in Amazon's cataloging system.

Understanding ASINs helps sellers, librarians and buyers navigate Amazon's listings and reconcile Amazon records with other product identifiers.