Generate Code 128 barcodes in bulk from a CSV or Excel file. Export print-ready PDF for Avery labels, high-resolution PNG, scalable SVG, or native ZPL commands for Zebra thermal printers — no row limit, no signup, no watermark. All barcode generation runs locally in your browser.
Generate Code 128 Barcodes Free →Paste values one per line, or upload a CSV or Excel file with hundreds of product codes. Choose which column to use as the barcode value.
Download an Avery-compatible PDF, high-res PNG ZIP, scalable SVG, or native ZPL for Zebra thermal printers — all at 300 DPI.
No row limit, no signup, no watermark. All processing is local — your SKUs and product codes never reach any server.
Paste values one per line, or upload CSV/Excel. Select the column containing your codes.
Choose Code 128 from the symbology picker. Set label size, paper format, and export type (PDF / PNG / ZPL).
Click Generate and download your ZIP, PDF, or ZPL file — ready for Avery sheets or thermal printers.
The standard for internal stock locations, bin numbers, and SKU tracking in warehouses and 3PL facilities.
FedEx, UPS, and DHL use Code 128 on shipping labels for package tracking and route sorting.
Small shops use Code 128 for in-house product labels without needing a GS1 barcode registration.
Track components and assemblies through manufacturing stages with Code 128 work-order barcodes.
Code 128 is a variable-length linear barcode that can encode the full 128-character ASCII set, including uppercase and lowercase letters, digits, and punctuation. It is one of the most compact and widely compatible 1D barcode formats in existence, supported by virtually every barcode scanner manufactured in the last 30 years.
Unlike retail formats such as UPC-A or EAN-13, Code 128 requires no GS1 membership or prefix registration. This makes it the default choice for internal inventory systems, shipping labels, and any application where the same organization controls both the label printer and the scanner.
| Property | Value |
|---|---|
| Symbology type | Linear (1D), continuous, variable length |
| Character set | All 128 ASCII characters (via three subsets) |
| Subsets | A (control + uppercase), B (upper + lowercase), C (numeric pairs) |
| Data length | Variable; practical limit ~48 characters |
| Check character | Mandatory, modulo-103, calculated automatically |
| Structure per character | 3 bars + 3 spaces = 11 modules |
| Quiet zone | Minimum 10× the narrowest bar width, each side |
| Typical X-dimension | 0.25 mm (10 mil) for laser; 0.19 mm (7.5 mil) at 300 DPI thermal |
| Registration required | None — no GS1 membership or prefix fee |
Every Code 128 character occupies exactly 11 modules, split into three bars and three spaces. That fixed-width structure is what makes the format "continuous" — there is no inter-character gap, so the bars pack tighter than in older formats like Code 39, which needs a narrow space between every character.
Code 128 has no mandated bar height, unlike retail formats where the specification fixes proportions. In practice, bar height should be at least 15 % of the barcode's total width, or about 6 mm minimum — whichever is greater. Taller bars give a handheld scanner more vertical tolerance, which matters when an operator scans at an angle or the label is curved around a bottle or a cable.
The human-readable text below the bars is optional to the specification but effectively mandatory in practice. If a barcode gets damaged or a scanner fails, a person needs to type the value manually. Our generator includes the text line by default and lets you replace it with a custom label — useful when the encoded value is a long internal SKU but the operator only needs to see a short bin code.
Code 128 defines three character subsets, and a single barcode can switch between them mid-string. Subset A covers uppercase letters, digits, and ASCII control characters. Subset B covers uppercase and lowercase letters plus digits. Subset C is the interesting one: it encodes two digits per 11-module symbol instead of one character, which makes a purely numeric value roughly twice as dense as the same value in subset A or B.
Our generator picks the optimal subset automatically and inserts shift codes where switching mid-string produces a shorter barcode. A 20-digit numeric value encoded in subset C occupies about the same physical width as a 10-character alphanumeric value in subset B. This is why a numeric-only SKU scheme fits on a smaller label than a mixed alphanumeric one of the same character count — worth knowing if you are still designing your SKU format.
Code 128 requires a check character, which the encoder derives by summing the weighted values of each symbol and taking the remainder modulo 103. Unlike UPC-A or EAN-13, this check character is not printed in the human-readable line — it exists purely inside the bar pattern. You never enter or calculate it, and a scanner that reads a Code 128 barcode has already verified it before reporting the value.
GS1-128 (formerly UCC/EAN-128) is not a separate symbology. It is a Code 128 barcode whose first data character is the FNC1 function character, signalling to the scanner that the payload follows GS1 Application Identifier syntax — structured fields such as (01) for GTIN, (10) for batch/lot, (17) for expiry date. Retail and pharmaceutical supply chains use GS1-128 on shipping cases. If a distributor asks for "GS1-128", they need the AI-formatted payload, not a different barcode type.
History: Code 128 was developed in 1981 by Computer Identics and standardised as ISO/IEC 15417. Its combination of full ASCII support, high density, and zero licensing cost is why it displaced Code 39 as the default choice for internal-use barcodes across logistics and manufacturing.
(01) for GTIN or (17) for expiry date. The bar pattern is generated by the same Code 128 encoder; only the data formatting differs. If a retail distributor or pharmaceutical supply chain asks for GS1-128, they need the AI-formatted payload, not a different symbology.