What Is a CODE128 Barcode?
CODE128 is a high-density linear barcode that can encode the full 128 ASCII character set — letters, numbers, punctuation and special characters. It was developed in 1981 and has become the dominant barcode format for logistics, shipping, and inventory management worldwide.
Unlike EAN-13 which is fixed at 13 digits, CODE128 has no set length. You can encode a short order number like "ORD-001" or a long reference like "WH-A12-SHELF-03-BIN-07". That flexibility is what makes it the go-to choice for internal systems.
💡 CODE128 vs EAN-13 in one sentence: EAN-13 is for retail products sold at checkouts. CODE128 is for everything else — logistics, warehouses, shipping, internal tracking.
Common Use Cases for CODE128
- Amazon FBA FNSKU labels — Amazon's FNSKU codes use CODE128. Enter your FNSKU (starts with X0 or B0) and generate the label image here for free.
- Shipping labels — Most carriers (DHL, UPS, FedEx) use CODE128 for tracking numbers on their labels.
- Warehouse inventory — Encode your SKU or internal product code for shelf labels and bin tags.
- Library systems — Book identification and tracking using alphanumeric codes.
- Healthcare — Patient wristbands, medication labels and sample tracking.
- Event tickets — Encode booking references for door scanners.
- Returns and RMA labels — Generate return authorization codes for your fulfillment workflow.
CODE128 vs Other Barcode Formats
| Format | Characters | Length | Best For |
|---|---|---|---|
| CODE128 | All ASCII | Variable | Logistics, inventory, shipping |
| EAN-13 | Numbers only | Fixed 13 | Retail product identification |
| CODE39 | Alphanumeric | Variable | Automotive, defense, older systems |
| UPC-A | Numbers only | Fixed 12 | North American retail |
| ITF-14 | Numbers only | Fixed 14 | Cartons and pallets |
Print Requirements for CODE128
Minimum Bar Width
The minimum bar width (called the X dimension) should be at least 0.25mm for standard scanners, and at least 0.19mm for high-resolution scanners. Most label printers at 300 DPI produce bars around 0.08mm per pixel — use a width multiplier of at least 2–3 in the generator for reliable scanning.
Minimum Height
CODE128 height should be at least 15% of the barcode length or 6.35mm, whichever is greater. Taller barcodes scan more reliably because scanners can compensate for slight vertical misalignment.
Download as SVG
For print production, always download the SVG version. SVG is a vector format that prints sharp at any size, while PNG can become pixelated when enlarged. Place the SVG in your label design software and scale to the required size.
✅ Amazon FBA tip: For FNSKU labels, set height to at least 25mm and width multiplier to 2. Amazon's scanner systems require a minimum quiet zone of 6.35mm on each side of the barcode.
Frequently Asked Questions
What is a CODE128 barcode?
CODE128 is a high-density barcode that encodes all 128 ASCII characters. It's the most widely used barcode in logistics, shipping and inventory management.
What is the difference between CODE128 and EAN-13?
EAN-13 encodes exactly 13 digits for retail products. CODE128 encodes variable-length alphanumeric data for logistics, shipping and inventory systems.
Can I use CODE128 for Amazon FBA?
Yes. Amazon FNSKU labels use CODE128. Enter your FNSKU code and generate the barcode image here for free.
Is there a character limit?
No hard limit, but longer content means a wider barcode. For practical scanning, keep content under 20 characters for small labels.