Every product on Amazon has an ASIN. If you sell, source, or research products, it is one of the first codes you need to understand. Once you know how to read an ASIN and look one up, finding the right products to sell gets a lot faster.
What does ASIN stand for?
ASIN stands for Amazon Standard Identification Number. It is a 10-character code made up of letters and numbers that Amazon assigns to every product in its catalogue. Think of it as the product's home address on Amazon. No two products share the same one.
What an Amazon ASIN looks like
An ASIN is always 10 characters long and usually starts with the letter B, for example B08N5WRWNW. You will find it on almost every product page, and it stays the same across listings, offers, and sellers for that exact product.
Books are the one exception. For books, the ASIN is the same as the 10-digit ISBN, so it can be all numbers instead of starting with a B.
How ASINs work and why every product has one
When a product is added to the Amazon catalogue for the first time, Amazon creates an ASIN for it. From that point on, every seller who offers that product sells under the same ASIN. That is what lets ten different sellers compete on one product page instead of creating ten separate listings.
This matters for you as a seller. When you source a product, you are really sourcing an ASIN. The reviews, the ranking, the Buy Box, and the sales history all live on that single ASIN.
ASIN vs UPC, EAN and FNSKU
ASINs are easy to mix up with the other codes you see when listing products. Here is the short version:
- UPC and EAN are global barcodes owned by the manufacturer. An EAN has 13 digits and is the standard across Europe. These exist outside Amazon.
- ASIN is Amazon's own internal ID. It only exists on Amazon and is tied to the catalogue, not to your inventory.
- FNSKU is the label Amazon puts on your physical units in an FBA warehouse. It links a specific unit to you as the seller.
If you want the full breakdown of every code, our Amazon barcodes guide walks through each one.
How to find an ASIN on Amazon
There are three quick ways to find the ASIN of any product:
- Check the URL. On a product page, the ASIN is the 10-character code right after /dp/ in the web address.
- Scroll to the product information section. Most listings show the ASIN in the details table further down the page.
- Use a lookup tool. A scanner or extension reads the ASIN for you and pulls the data you actually care about, like price history and sales estimates.
Why ASINs matter for arbitrage sellers
For online and retail arbitrage, the ASIN is where your research starts. You find a product at a shop like Otto, Argos, or MediaMarkt, then match it to its ASIN on Amazon to check the selling price, fees, and demand.
ASINs also power reverse sourcing. Instead of starting from a shop, you start from a profitable ASIN on Amazon and work backwards to find a supplier selling it cheaper. This is the idea behind Amazon-to-Amazon (A2A) flips and reverse search sourcing.
Find profitable products faster with ProfitGo and ProfitPath
Looking up ASINs by hand is fine for one product. It falls apart when you are checking hundreds. That is where our tools come in.
ProfitGo is the easy place to start. Scan a barcode or pull up an ASIN on your phone or in Chrome, and it shows you the FBA fees, BSR, and estimated sales in seconds. It is built for beginners and retail arbitrage on the go, with a 7-day free trial.
When you are ready to scale, ProfitPath runs ASIN-level sourcing across 1,000+ suppliers and 200M+ products. Reverse Search and A2A Search find profitable ASINs at volume, and Price Alerts watches their prices around the clock so you never miss a drop.
Frequently asked questions
How many characters is an ASIN?
An ASIN is always 10 characters long. It is a mix of letters and numbers and usually starts with a B, except for books, where it matches the 10-digit ISBN.
Can two products have the same ASIN?
No. Each ASIN is unique to one product in the Amazon catalogue. Every seller offering that exact product sells under the same ASIN, but the same product never has two different ASINs in one marketplace.
Is an ASIN the same in every Amazon marketplace?
Not always. A product can have a different ASIN on Amazon UK than on Amazon Germany. When you source across marketplaces, always check the ASIN in the marketplace you plan to sell in.
Do I need to create an ASIN to sell?
Only if the product is not already on Amazon. If it exists in the catalogue, you list against the existing ASIN. If it is brand new, Amazon creates one when you add it.
Once you can read an ASIN, find it in seconds, and look up what a product actually sells for, sourcing stops feeling like guesswork. Start by scanning a few products with ProfitGo and see how the numbers look before you buy.
