Free SKU Generator

SKU Generator FAQs

What is an SKU?

A SKU (Stock Keeping Unit) is a unique alphanumeric code that a business creates to track individual products and variants in its inventory. A typical SKU is 8–12 characters and encodes details such as product type, size, colour, or scent. Unlike universal barcodes, SKUs are internal identifiers you control — the format and naming convention belong entirely to your business.

Why do I need an SKU for my products?

SKUs let you identify any specific product variant instantly, making it easier to manage stock levels, track sales performance, and prevent fulfilment errors. They are especially valuable when you sell variations of the same product — different sizes, scents, or colours — across multiple sales channels like Etsy, Shopify, or your own website. Craftybase tracks your SKUs across all connected sales channels so inventory counts update automatically with every sale.

How many characters should an SKU have?

There's no strict rule, but most sellers prefer 8-12 characters for readability and consistency. Longer SKUs can capture more product information but may be harder to manage. The Craftybase SKU Generator can help you strike the right balance between detail and simplicity.

Can I change my SKUs after I generate them?

Yes. You're free to edit your SKUs at any time, although it's best to finalize a consistent SKU format early to avoid confusion. If you sell on multiple platforms, remember to update the SKUs everywhere to maintain consistency and accurate product tracking.

Are SKUs the same as barcodes or UPCs?

No — SKUs, barcodes, and UPCs are three distinct identifiers. A SKU is an internal code you create for your own inventory management, in any format you choose. A UPC or EAN is a globally standardised 12- or 13-digit code issued by GS1 for external retail and supply chains. A barcode is the visual, machine-readable representation of any underlying code — your SKU can be printed as a barcode once the codes are set.

What characters can I use (and avoid) in an SKU?

Use letters A-Z and numbers 0-9. Dashes (-) or underscores (_) are safe separators. Avoid spaces and special characters such as #, &, /, or accented letters, and consider skipping easily confused letters like O and I.

Is there a maximum SKU length for Shopify, Etsy or Amazon?

Shopify caps SKU strings at 16 characters and recommends 4–8 for readability. Etsy and Amazon do not set strict character limits, but best practice is to stay under 40 characters. Most sellers keep SKUs in the 8–12 character range, which balances readability with enough detail to distinguish every variant.

Do my SKUs have to be unique across all sales channels?

Yes — each product variant should have a unique SKU across every marketplace you sell on. Duplicate SKUs across channels cause mismatched inventory counts, analytics errors, and can trigger duplicate-listing conflicts on platforms like Shopify and Etsy. Unique SKUs are the single source of truth that keeps stock levels accurate when you sell in multiple places.

Can I convert these SKUs into barcodes later?

Yes. Any alphanumeric SKU can be encoded into a barcode format such as Code-128 or a QR code using standard label-printing software or free online generators — the underlying SKU text remains unchanged. This means you can print shelf labels, product tags, or shipping stickers that scan directly into your inventory system.

Should I reuse an SKU when a product is discontinued?

No. Retire the code instead. Reusing an SKU can corrupt historical sales data and trigger duplicate-SKU conflicts on marketplaces.

What's the best separator—dash or underscore?

Both are technically safe, but dashes tend to print and scan more clearly on labels. Avoid other separators like spaces, slashes, or periods, which can cause import or URL encoding issues.

Can leading zeros cause problems in spreadsheets?

Yes. Excel and Google Sheets strip leading zeros unless the cells are formatted as text or with a custom number format. Format columns before import or avoid placing zeros at the start of the SKU or prefix the code with a non-zero character to keep the zeros intact.

How does Craftybase use SKUs to manage inventory automatically?

Craftybase assigns your SKUs to products and materials, then automatically adjusts inventory counts as you sell, manufacture, or restock. When you connect a sales channel such as Shopify or Etsy, every incoming order reduces the correct SKU's stock level in real time. This removes the need to manually reconcile inventory spreadsheets and prevents overselling across multiple channels.

What is the best SKU format for products with many variants?

For products with multiple variants — such as scent, size, and colour — the most reliable format uses fixed segments: Category–Product–Variant1–Variant2. A lavender soy candle in a 12 oz jar could become CND-SOY-LAV-12OZ. This pattern keeps every SKU consistent and human-readable while ensuring each combination gets a unique code with no overlap.