The Amazon Standard Identification Number (ASIN) is a unique identification number assigned by Amazon.com and its partners for product identification within the Amazon.com organization.^[1] Amazon.ca,^[1] Amazon.co.uk,^[2] Amazon.de,^[3] Amazon.fr,^[4] Amazon.it,^[5] Amazon.co.jp^[6], Amazon.cn^[7], and Amazon.es^[8] also use ASINs.

ASINs are unique worldwide: one ASIN can only ever refer to one product. 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.

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.^[9]

ASIN in Amazon URLs[link]

On Amazon's USA-targeted web site, a product's web address (URL) may contain its ASIN in any of the following formats:

http://www.amazon.com/exec/obidos/tg/detail/-/ASIN-VALUE-HERE

http://www.amazon.com/gp/product/ASIN-VALUE-HERE

http://www.amazon.com/o/ASIN/ASIN-VALUE-HERE

http://www.amazon.com/dp/ASIN-VALUE-HERE

http://www.amazon.com/dp/product/ASIN-VALUE-HERE

http://www.amazon.com/<ProductName>/dp/ASIN-VALUE-HERE

where ASIN-VALUE-HERE is replaced by the actual ASIN.

For example, using the "dp" ("detail page") URL format, the 4th paperback edition of Strunk and White's The Elements of Style, whose ISBN is 0-205-30902-X, would be found at:

http://www.amazon.com/dp/020530902X

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[link]

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:

http://amazon.com/Elements-Style-Fourth-William-Strunk/dp/020530902X/ref=sr_1_7?ie=UTF8&qid=1307695052&sr=8-7

This can be shortened to:

http://amazon.com/dp/020530902X

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:

http://amzn.com/ASIN-VALUE-HERE

References[link]