Barcode Generator - Create Code 128 Barcodes Online

Generate Code 128 barcodes online for free with this barcode generator . Create scannable barcodes for products, inventory, retail SKUs, shipping labels, and asset tags — all compatible with virtually every laser and image scanner, ready to print in seconds. No registration, no watermarks, and the barcode downloads as a high-resolution PNG.

Code 128 is a one-dimensional (linear) barcode: it encodes data as a sequence of vertical bars and spaces of varying widths that a scanner reads in a single pass. Unlike a QR code , which stores data in a 2D grid, a linear barcode holds a single short string. That makes it ideal for product IDs, SKUs, and serial numbers where you want a compact, universally-scannable identifier.

Why Use an Online Barcode Generator?

An online barcode generator lets you produce a Code 128 barcode the moment you need one, without buying label software or installing a plugin. Type a product code, SKU, or serial number and the tool renders the bars instantly, ready to copy into an invoice, paste onto a packaging design, or print onto an adhesive label. The output is a clean PNG that scales without quality loss.

Code 128 is the most flexible linear barcode maker format because it supports all 128 ASCII characters — letters, digits, and symbols — in a compact width. That is why it is the default for shipping (GS1-128), warehouse inventory, and point-of-sale systems worldwide. Because this create barcode online tool runs entirely in your browser, your product codes never leave your device, which matters for confidential SKUs and unreleased catalogues.

Live Example

Type any alphanumeric value and the generator renders it as a Code 128 barcode on the right. The bars represent your value encoded as a sequence of widths; the scanner decodes those widths back into the original text:

PROD-000123456

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How to Use Barcode Generator

1. Enter Data: Type or paste the text, numbers, or data you want to encode into the barcode.
2. Generate Barcode: The tool automatically creates a barcode image from your input data.
3. Preview and Download: Preview your barcode and download it in high-quality format for printing or digital use.

Key Features

• ✅ Support for Code 128 barcode format
• ✅ Real-time barcode preview as you type
• ✅ Instant download in high-quality image format
• ✅ Compatible with most barcode scanners
• ✅ Easy-to-use interface for quick barcode creation
• ✅ No registration or sign-up required

Common Use Cases

• Product Labeling: Create barcodes for retail products, packaging, and inventory items.
• Inventory Management: Track and manage stock with unique barcode identifiers.
• Asset Tracking: Label equipment, tools, and company assets for easy identification.
• Library Systems: Generate barcodes for books, media, and library resources.
• Event Management: Create barcodes for tickets, passes, and attendee badges.

Benefits of Using Our Barcode Generator

• ✅ Completely free to use with no limitations
• ✅ Fast barcode generation in real-time
• ✅ High-quality output suitable for printing
• ✅ Works on all devices - desktop and mobile
• ✅ No data storage - your information stays private

About Barcodes — How They Work

A barcode is a machine-readable representation of data. The most common retail style is the one-dimensional (linear) barcode, which prints data as parallel vertical bars and spaces of different widths. A scanner shines a light or laser across the bars, measures the widths of the dark and light regions, and converts that pattern back into the original characters using a defined symbology .

This tool generates Code 128 , one of the most powerful linear symbologies. Code 128 can encode all 128 ASCII characters (digits, letters, and symbols) and comes in three subsets: Code 128 A (uppercase letters and control characters), Code 128 B (upper- and lowercase letters), and Code 128 C (pairs of digits, which are the most compact). The generator auto-selects the best subset for your input and appends a check digit — a calculated character that lets a scanner detect a misread, so a damaged or smudged code is rejected rather than silently returning the wrong value.

Code 128 is the backbone of shipping labels (GS1-128), warehouse bins, and asset tags because it is compact and universally supported. It is different from retail point-of-sale codes like EAN-13 or UPC-A (which have a fixed 12–13 digit length) and from QR codes (which are two-dimensional and hold far more data). For anything longer than a short ID — a URL, contact, or Wi-Fi login — reach for a QR code instead. To turn a generated label graphic into a raster file, use SVG to PNG .

Common Errors and How to Fix Them

• Barcode will not scan: The value may be too long, making individual bars too thin for low-resolution laser scanners. Keep encoded strings concise (ideally under 40–50 characters); switch to a 2D QR code for long URLs or rich text.
• Scanner returns unexpected characters: Code 128 supports full ASCII, but older legacy handheld scanners might be hardwired to standard alphanumeric Code 39. Confirm whether your target inventory hardware expects Subset B or Subset C.
• Missing Quiet Zone margin: Linear barcodes require a blank white margin (at least 10 times the width of the thinnest bar) on both sides. Never crop or place borders right up against the edge of the bars.
• Low print contrast or smudged thermal print: Ensure high-contrast pure black bars on a pure white or matte surface. Thermal transfer ribbons with poor heat settings can bleed ink and alter bar widths.

Code 128 Subsets: How Numbers and Text Are Encoded

Code 128 automatically shifts between three internal character subsets to achieve maximum compression and shortest printed width:

Barcode Symbology Comparison: Which Format Do You Need?

Selecting the correct barcode standard depends on your industry requirements and the data you need to encode:

How to Generate Code 128 Barcodes in Code

Generate Code 128 barcodes programmatically inside your web or backend applications:

// Using JsBarcode in browser or SVG renderer
import JsBarcode from 'jsbarcode';

// Render into an SVG or Canvas element
JsBarcode('#barcodeCanvas', 'SKU-987452', {
  format: 'CODE128',
  lineColor: '#000000',
  width: 2,
  height: 80,
  displayValue: true
});

import barcode
from barcode.writer import ImageWriter

# Generate Code 128 barcode as PNG
code128 = barcode.get_barcode_class('code128')
bar = code128('SKU-987452', writer=ImageWriter())
bar.save('barcode_output')