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ListIQ Pro

Free SKU Generator for Online Sellers

A SKU is the one identifier you control. The marketplace assigns the ASIN, GS1 sells you the barcode, but the SKU is yours — which means it is also the one that gets invented ad hoc, drifts between channels, and stops being readable about two hundred products in.

Build the format once here. Enter your segments, pick a separator, and expand it across every variant you sell. Nothing is sent anywhere.

Free, no signup, runs entirely in your browser — nothing you type is sent anywhere. Last updated .

Build the format

Leave a segment blank to drop it. The order you see is the order it appears in the code.

Separator

Result

Parent SKU
ACME-MUG-CERAMIC12-BLU

22 / 40 characters

4 child SKUs
  • ACME-MUG-CERAMIC12-BLU-S24
  • ACME-MUG-CERAMIC12-BLU-M24
  • ACME-MUG-CERAMIC12-BLU-L24
  • ACME-MUG-CERAMIC12-BLU-XL25

What it does

Inside the sku generator

  • Parent SKU plus every variant combination
  • Warns past Amazon's 40-character seller SKU limit
  • Flags leading zeros before a spreadsheet eats them
  • Copy as a list or download as CSV

Guide

SKU Generator: what actually matters

What a good SKU format looks like

Short, alphanumeric, hyphen-separated, and readable at a glance. The structure most sellers converge on is BRAND-CATEGORY-PRODUCT-VARIANT. Someone in your warehouse should be able to read ACME-MUG-CERAMIC12-BLU off a shelf label and know which unit it is without opening a spreadsheet. That is the entire test — if the code needs a lookup table to interpret, it is an ID, not a SKU.

Parent and child SKUs for variations

Amazon, Walmart and Shopify all use a parent/child model for variation families. The parent represents the style and owns the product page; each child represents one buyable combination of colour and size. Generating the parent and every child in one pass is what makes a variation family import cleanly on the first attempt rather than the third.

The mistakes that corrupt a catalogue silently

Never reuse a retired SKU — marketplaces keep historical sales and review data attached to it, and reuse can merge two unrelated products into one listing. Avoid spaces, slashes and ampersands, which break CSV uploads and label printers. And never let a SKU start with a zero: Excel and Google Sheets strip leading zeros from anything they read as a number, so the code silently changes every time the file is opened and saved.

Do not encode anything that changes

Price, supplier and cost do not belong in a SKU. They change, and when they do the code becomes a lie you cannot correct without retiring the SKU — which you have just been told not to do. Encode what is permanent about the product: what it is, and which variant it is.

Character limits across the marketplaces

Amazon caps seller SKUs at 40 characters, and it is the strictest of the majors. eBay and Shopify allow considerably more. Since the point of a SKU is to be identical everywhere your inventory syncs, the strictest platform in your stack sets the real limit — which is why this tool warns at 40 regardless of where you are listing.

FAQ

Common questions

Is this SKU generator free?

Yes. It runs entirely in your browser with no account and no limit. Nothing you type is transmitted or stored.

What is the difference between a SKU and a UPC or EAN?

A SKU is your own internal code and can be anything you choose. A UPC or EAN is a globally unique barcode number issued through GS1 and used to identify a product across every seller who carries it. You invent the SKU; you buy the barcode. If you need the second one, the barcode generator on this site calculates valid check digits.

Should I use the same SKU on Amazon and Shopify?

Yes, and it matters more than it sounds. Identical SKUs across channels are what keep inventory sync accurate in a 3PL, an ERP or a repricer. Divergent SKUs per channel are the most common cause of overselling.

Should SKUs include the year or season?

Only if you genuinely re-release the product each season, as apparel and seasonal decor do. For an evergreen catalogue item a season code adds noise, makes reorders harder to trace, and pushes you toward the character limit for no benefit.

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Browse every ListIQ Pro tool — free browser calculators and the in-app generators, grouped by what they do.

Turn your SKUs into live listings

A SKU identifies the product. It does not write the title, the bullets or the backend keywords. ListIQ Pro generates the full field set your marketplace asks for, from one photo.

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