Amazon Standard Identification Number
The Amazon Standard Identification Number (ASIN) is a 10-character alphanumeric unique identifier assigned by Amazon.com and its partners for product identification within the Amazon.com organization. Amazon.ca, Amazon.co.uk, Amazon.de, Amazon.fr, Amazon.it, Amazon.co.jp, Amazon.cn, and Amazon.es also use ASINs.
Although ASINs used to be unique worldwide, global expansion has changed so that ASINs are only guaranteed unique within a marketplace. The same product may be referred to by several ASINs though, and different national sites may use a different ASIN for the same product. In general, ASINs are likely to be different between the country sites unless they are for a class of product where the ASIN is based on an externally-defined and internationally consistent identifier, such as ISBN for books. (Where the ASIN is the same across sites, it is likely to be because the 3rd party creator of the product information was careful to quote an existing ASIN when creating the product in second and subsequent countries, or the subsequent product creation offered exact duplicate information and long enough after the initial creation to allow indexes to have been updated. Also, ISBNs can vary between countries for the same book if a separate print run or edition was published for the country.)
Each product sold on Amazon.com is given a unique ASIN. For books with 10-digit International Standard Book Number (ISBN), the ASIN and the ISBN are the same. Books without a 10-digit ISBN (including those with only a 13-digit ISBN) and other products are also assigned ASINs. ASINs are also used for other items used by Amazon.com (and subsidiaries), such as businesses in the yellow pages (on A9.com) and OpenSearch feeds.
Proponents of the free culture movement, such as Wikipedia co-founder Jimmy Wales, have criticized the ASIN as an example of a proprietary product identifier, arguing that it draws producers—especially smaller ones—into a lock-in with Amazon, and have proposed the creation of an open alternative where producers could register product IDs for a marginal fee without proprietary control, and the resulting databases would be available under a free license.
ASIN in Amazon URLs 
where ASIN-VALUE-HERE is replaced by the actual ASIN.
Similar URLs can be constructed for Amazon web sites in other countries:
- Canada: http://www.amazon.ca/dp/020530902X
- China: http://www.amazon.cn/dp/020530902X
- France: http://www.amazon.fr/dp/020530902X
- Germany: http://www.amazon.de/dp/020530902X
- Italy: http://www.amazon.it/dp/020530902X
- Japan: http://www.amazon.co.jp/dp/020530902X
- Spain: http://www.amazon.es/dp/020530902X
- United Kingdom: http://www.amazon.co.uk/dp/020530902X
However, not all sites carry all titles; for example, the ASIN B000J8VLEC only appears on Amazon.jp.
Also note that the Kindle edition of a book will not use its ISBN as the ASIN.
Shortening the URL 
In cases where a shorter URL is desired than the one provided by default by the Amazon web site—for example, for use in a text message—the prefix "www." may be removed, and, if present, any text after the ASIN itself may be dropped from the URL, as well as any text between the domain name (e.g., amazon.com) and the first part of the resource path in the cases listed above (e.g., /gp or /dp).
For example, if one uses Amazon's search feature to find the Strunk and White book mentioned above, the resulting URL might look like:
This can be shortened to:
In addition, the domain name itself may be shortened to amzn.com (USA site only), in which case everything except the domain and ASIN may be dropped. This results in the shortest possible form:
- "Amazon.ca Help: Product Identifiers". Amazon.ca. Retrieved 25 May 2011.
- "Amazon.co.uk Help: What is an ASIN?". Amazon.co.uk. Archived from the original on 3 June 2011. Retrieved 25 May 2011.
- "Amazon.de Hilfe: Was ist eine ASIN (ISBN)?" (in German). Amazon.de. Retrieved 25 May 2011.
- "Amazon.fr Aide: ASIN et ISBN : qu'est-ce que c'est ?" (in French). Amazon.fr. Retrieved 25 May 2011.
- "Amazon.it Aiuto: Condizioni Generali di Uso e Vendita." (in Italian). Amazon.it. Retrieved 25 May 2011.
- "ISBN/ASINについて" (in Japanese). Amazon.co.jp. Archived from the original on 14 May 2011. Retrieved 25 May 2011.
- "EXCO 宜适酷 IP-18皮套(Fit iPad2 黑色 适用于苹果平板电脑iPad2)". Retrieved 2012-01-22.
- "Amazon.es Ayuda: Localización de los códigos ASIN e ISBN." (in Spanish). Amazon.es. Retrieved 29 Oct 2011.
- Jimmy Wales: Ten Things That Will Be Free. Wikimania 2005 keynote, August 2005. Section "8. Free the Product Identifiers!" Video (1:07:51)