How to Create SKUs and Barcodes for Your Products (Free, No Software)
Whether you run a Shopify store with 20 products or a warehouse with 20,000, every item needs a way to be uniquely identified. SKUs and barcodes are the backbone of that system — yet most small business owners either skip them entirely or cobble together inconsistent codes that cause headaches down the line. Here's how to do it right from the start.
What Is a SKU (and Why It's Not the Same as a Barcode)?
A SKU (Stock Keeping Unit) is an internal code your business creates to identify a product and its variants. SKUs are entirely up to you — they encode whatever information is useful to your operations, such as category, color, and size. For example, TSH-BLU-L might mean “T-Shirt, Blue, Large.” A barcode, on the other hand, is a machine-readable visual representation of a number — often a standardized one (like UPC or EAN) used by retailers and shipping carriers. You can put your SKU number inside a barcode, but they serve different purposes: SKUs are for your internal inventory system; barcodes are for scanners at checkouts and warehouses.
How to Build a Good SKU System
The best SKU schemes are short, readable, and consistent. A practical approach is to use a three-part format: a category prefix, an attribute code, and a unique sequence number. For clothing, that might be JKT-RED-001 (jacket, red, first variant). A few rules that save headaches later: avoid spaces and special characters except hyphens; never reuse a SKU even after a product is discontinued; keep all codes the same length if possible; and document your system so anyone on your team can decode a code at a glance. Avoid using manufacturer part numbers as your SKUs — they're often long, cryptic, and will change if you switch suppliers.
Barcode Types: Which One Do You Need?
The barcode format you need depends on where you're selling. Code128 is the most versatile option for internal use — it encodes any alphanumeric string, making it ideal for printing on packing slips, shelf labels, and pick tickets. If you're selling in retail stores or on Amazon, you'll likely need a UPC-A (12 digits) or EAN-13 (13 digits), which require a registered prefix from GS1. For internal warehouse labels and shipping workflows, Code128 with your custom SKU is perfectly sufficient and free to generate.
Generating SKUs and Barcodes for Free
You don't need expensive inventory software just to create scannable barcodes. Our SKU & Barcode Generator lets you define your SKU naming pattern, bulk-generate codes for multiple variants, and export print-ready Code128 barcodes — entirely in your browser with no upload, no account, and no subscription. You can preview each barcode before downloading and export them as PNG images ready to drop into a label template or packing slip.
Where to Print Your Barcodes
Once you have your barcode images, you have several printing options. For product labels, standard 4×6 thermal label printers (like those from Zebra or Dymo) are the most efficient — they print adhesive labels that stick directly on packaging. For lighter use, ordinary laser or inkjet printers work fine on label sheets. Make sure the printed barcode is at least 2.5 cm (1 inch) wide and printed at a high enough DPI (300+) for reliable scanning. Test every label with a barcode scanner app on your phone before committing to a large print run.
Integrating SKUs into Your Workflow
Once your codes are consistent, the real payoff begins. Import your SKU list into your e-commerce platform (Shopify, WooCommerce, Etsy), your shipping software, and your spreadsheet-based inventory tracker. When an order comes in, a quick scan of the barcode confirms the right item is packed — dramatically reducing mis-picks. Pair your SKU system with a Packing Slip Generator so every shipment includes a scannable document that matches your internal records. Starting with clean, unique codes from day one makes every future automation far easier to build.