Amazon ASIN Lookup Tool

Every product page on Amazon is keyed by a 10-character ASIN (Amazon Standard Identification Number). Sellers need ASINs constantly: to match offers against existing catalog pages, to run Sponsored Products campaigns, to file infringement or suppression cases, to pull reviews, and to map their own SKUs against Amazon's catalog when syncing inventory. The problem this tool solves is mechanical but real — ASINs live inside long, messy URLs, and copying them out one by one from fifty supplier links is exactly the kind of work that produces typos.

Where the ASIN hides in an Amazon URL

Amazon uses several URL shapes for the same product: /dp/B0BSHF7WHW on standard pages, /gp/product/B0BSHF7WHW on older links, /gp/aw/d/… on mobile, /product-reviews/… on review pages, and /gp/offer-listing/… on the offers page. In every case the ASIN is the 10-character block after the marker — everything after it (slashes, ?th=1, tracking parameters) is noise. The extractor above recognizes all of these shapes across every Amazon country domain, which is why you can paste a mixed list of German, US, and UK links and get one clean ASIN column back.

ASIN vs EAN vs UPC vs GTIN

An ASIN is Amazon-internal; a GTIN (the family that includes EAN-13 and UPC-A) is the global GS1 barcode printed on the physical product. Amazon uses the GTIN as the matching key: when you submit a product with an EAN that already exists in the catalog, your offer attaches to the existing ASIN rather than creating a duplicate. That is also why the two identifiers are constantly converted in both directions — and why the conversion is a lookup, not a formula. A UPC-A is simply an EAN-13 with the leading zero removed, which the checker above converts instantly; but no algorithm can turn either of them into an ASIN, because Amazon assigns ASINs sequentially as products enter its catalog.

Three ways to convert an EAN to an ASIN

Catalog search (free, manual): search the EAN on the Amazon marketplace you sell in — the marketplace buttons above build these searches for you. Amazon indexes barcodes, so an exact-match EAN almost always returns the right product; the ASIN is then in the product URL. Seller Central (free, semi-bulk): under "Add Products", paste EANs or UPCs directly — Amazon shows the matching catalog entries with their ASINs, and this is the authoritative check before creating an offer. SP-API (programmatic, bulk): the Catalog Items API accepts identifier lists and returns ASIN matches at scale — this is what listing automation software uses under the hood when it syncs a store catalog to Amazon.

Why books are different

For books, Amazon did not invent a new identifier — the ASIN is the ISBN-10, check digit and all. That is why the validator above runs a real ISBN-10 mod-11 check (including the trailing "X" case) instead of just pattern-matching: a mistyped book ASIN usually fails its check digit, which catches errors that a format check would let through. Newer books have ISBN-13s starting 978, which converts back to the ISBN-10/ASIN by dropping the prefix and recalculating the check digit.

Working across marketplaces

If you sell on more than one Amazon marketplace — or beyond Amazon on Allegro, Kaufland, bol.com, or eMAG — identifier hygiene compounds: the same EAN should map to the right catalog entry on every channel, and mismatches surface as duplicate listings, suppressed offers, or orders against the wrong variant. Keeping one clean product catalog and letting integration software handle the per-marketplace matching is the scalable version of what this page does manually.