Barcode generator for Amazon sellers
Three different barcodes get called "the Amazon barcode" and they do different jobs. Here is which one you need, and a generator for it.
EAN-13 — enter 12 digits and the check digit is calculated for you, or paste all 13.
Loading barcode engine…
Free, unlimited, no account required. Nothing you type is sent to our servers — the barcode is drawn in your browser.
FNSKU, UPC and ASIN — which is which
| Code | What it is | Who issues it | Where it goes |
|---|---|---|---|
| UPC / EAN | A GTIN identifying the product globally | GS1 (you licence it) | Required to create most new listings |
| FNSKU | Amazon's own code tying a unit to your seller account | Amazon, in Seller Central | Printed on each unit sent to FBA |
| ASIN | Amazon's internal catalogue identifier | Amazon, automatically | Not printed on anything |
The practical sequence: you licence a GTIN from GS1 and use it to create the listing. Amazon then issues an FNSKU for that listing, and that is the barcode that goes on the physical unit before it ships to a fulfilment centre. FNSKUs are Code 128, which is why this page opens on that format.
Generating an FNSKU label
- In Seller Central, open Manage Inventory and find the listing.
- Choose Print item labels — the FNSKU looks like
X001ABCDEF. - Paste that value into the generator above with Code 128 selected.
- Download the SVG and place it on your label template, or use Amazon's own PDF if you prefer.
Amazon's label requirements: between 1×2 inches and 2×3 inches, printed in black on white non-reflective stock, with the barcode fully covering any manufacturer barcode already on the unit. A code that is partially visible underneath causes receiving errors.
You cannot avoid GS1
Amazon validates GTINs against the GS1 registry. Barcode numbers resold cheaply on third-party marketplaces were originally issued to a different company, so the registry lookup returns the wrong brand and the listing is suppressed.
If you are building a brand, licence a GS1 company prefix directly. It is also a prerequisite for Amazon Brand Registry.
There is a GTIN exemption route for genuinely unbranded or handmade goods, but it is applied for per category and is not a general workaround.
After the box arrives
The FNSKU's job ends at the fulfilment centre. It does nothing once the customer opens the package.
That is where a QR code earns its place: a dynamic code inside the box can carry setup instructions, a warranty registration, a review request or a direct reorder link — and because Amazon does not give you the customer relationship, this is often the only channel you control.
Because the code is dynamic you can repoint it after thousands of units have shipped. Print a review request for launch, then switch the same code to a reorder page once you have traction.
Frequently Asked Questions
What barcode format is an FNSKU?
Code 128. Select it in the generator above, paste the FNSKU value from Seller Central, and download.
Do I need a UPC to sell on Amazon?
For most categories yes — a GS1-licensed GTIN is required to create the listing. Amazon validates it against the GS1 registry, so cheap resold numbers fail. A GTIN exemption exists for some unbranded and handmade categories.
Can I use one barcode for FBA and retail?
No. Retail uses the UPC or EAN on the packaging. FBA units need the FNSKU label applied over it, so Amazon can attribute the unit to your account. Commingled inventory is the exception, and most sellers avoid it.
What size does an FBA label need to be?
Between 1×2 and 2×3 inches, black on white, non-reflective, and fully covering any existing manufacturer barcode.
Can I generate FNSKU labels in bulk?
Amazon can produce a label PDF for a whole shipment from Seller Central, which is the simplest route. If you need custom label artwork at volume, bulk generation from CSV is available in the dashboard on paid plans.
Own the customer Amazon won't give you
A dynamic QR code in the box — warranty, reorder, review request — is the one channel you control. Repoint it any time without reprinting.
7-day free trial, no credit card. Barcodes stay free forever.