A SKU (stock-keeping unit) is an internal code your own systems assign. Unlike a barcode, no external standards body governs the format, so most of the work goes into settling on a consistent pattern and then applying it to every product variant without typos or accidental collisions.

This generates SKUs from a template pattern, expands attribute lists like colour and size into every combination automatically, and flags duplicates before they reach your catalog.

When you'd use this

Setting up a new product line with variants. Enter a pattern once (say, {BRAND}-{CAT:3}-{COLOR:3}-{SIZE}-{SEQ:4}), list the colour and size options, and get every SKU for the full variant matrix at once instead of typing each one by hand.

Running an existing SKU list through the collision check before a bulk import is worth the minute it takes. Two attribute values that abbreviate to the same three letters, say "Forest Green" and "Fern Green" landing on a similar code, is the most common way duplicate SKUs slip through.

Common errors

A "duplicate" flag means two different attribute combinations produced the exact same SKU string. Almost always an abbreviation rule like {COLOR:3} has truncated two different values down to identical characters. Widening that field's character count, or picking less similar attribute names, usually clears it.

The "too long" warning exists because several marketplaces cap SKU length around 40 characters; a SKU that's fine internally can still be silently truncated or rejected on import elsewhere.

Frequently asked questions