CODE128 Auto mode uses the most efficient character set based on your input.
CODE128A includes uppercase letters, numbers, and special control characters.
CODE128B includes uppercase and lowercase letters, numbers, and symbols.
CODE128C encodes pairs of digits efficiently, ideal for numeric data only.
CODE128 Character Sets
CODE128 is a high-density barcode that can encode all 128 ASCII characters. It has three subtypes:
| Type | Character Set | Best For |
|---|---|---|
| CODE128A | Uppercase letters, numbers, special control characters | Industrial applications with control characters |
| CODE128B | Uppercase & lowercase letters, numbers, symbols | Text with mixed case or symbols |
| CODE128C | Numbers only (encoded in pairs) | Numeric data (high density) |
| CODE128 Auto | All characters (auto-selects optimal encoding) | Mixed data types (general purpose) |
Alphanumeric Example
Shipping Label Example
Numeric Example (CODE128C)
CODE128 vs Other Barcode Types
| Feature | CODE128 | CODE39 | EAN/UPC |
|---|---|---|---|
| Character Set | All 128 ASCII characters | 43 characters (uppercase, numbers, symbols) | Numbers only |
| Density | High density | Low density | Medium density |
| Length | Variable length | Variable length | Fixed length |
| Primary Use | Logistics, inventory, shipping | Industrial, government, healthcare | Retail products |
| Check Digit | Mandatory (built-in) | Optional (Mod 43) | Mandatory |
| Special Features | Auto character set switching for optimal density | Self-checking, widely compatible | Fixed format, universal retail standard |
CODE128 Barcode Generator: High-Density Barcodes for All Applications
CODE128 is one of the most versatile and efficient barcode symbologies available, capable of encoding all 128 ASCII characters in a high-density format. Our free online CODE128 generator allows you to create standards-compliant barcodes instantly for logistics, shipping, inventory management, and a wide range of industrial applications.
What is a CODE128 Barcode?
CODE128 was developed in 1981 as a high-density barcode symbology capable of encoding all 128 ASCII characters. Unlike older barcode formats that were limited to numeric data or uppercase letters, CODE128 can represent the full range of standard text characters, including lowercase letters, special symbols, and control characters. This versatility, combined with its compact size, has made CODE128 the preferred choice for applications where space is limited and data requirements are complex.
CODE128 Subtypes and When to Use Them
CODE128 has three subtypes (A, B, and C), each optimized for different character sets:
- CODE128A: Includes uppercase letters, numbers, and control characters (ASCII 00-95). This subtype is ideal for applications that need to encode control characters, such as EDI (Electronic Data Interchange) or technical specifications.
- CODE128B: Includes all standard printing characters (ASCII 32-127), making it perfect for text data that includes both uppercase and lowercase letters along with standard symbols.
- CODE128C: Optimized for numeric data only, encoding pairs of digits in a single character for maximum density. This makes it about twice as efficient as other subtypes when encoding strings of numbers, such as serial numbers or product codes.
Our generator supports "Auto" mode, which automatically switches between these subtypes to create the most compact barcode possible based on your input data.
Applications for CODE128 Barcodes
CODE128 is widely used across numerous industries due to its versatility and efficiency:
- Logistics and Shipping: Package tracking, shipping labels, and inventory management
- Healthcare: Patient identification, medication tracking, and laboratory sample management
- Manufacturing: Work-in-progress tracking, quality control, and component labeling
- Document Management: File tracking, records management, and archiving
- Retail Supply Chain: Carton and pallet labeling, inventory control, and distribution center operations
Advantages of CODE128 Over Other Barcode Types
CODE128 offers several advantages that have made it a preferred choice for many applications:
- High Information Density: CODE128 is one of the most compact linear barcode formats, allowing you to encode more data in less space.
- Full ASCII Support: Unlike formats like CODE39 that require special sequences for lowercase letters or symbols, CODE128 natively supports the full ASCII character set.
- Reliable Error Detection: CODE128 includes a built-in check character that provides excellent error detection capabilities.
- Variable Length: The format supports variable-length data, unlike fixed-length retail barcodes such as EAN or UPC.
- Industry Standard: CODE128 is supported by virtually all barcode scanners and is recognized across global supply chains.
CODE128 Technical Specifications
CODE128 barcodes follow specific technical standards to ensure reliable scanning across all environments:
- Symbology: Continuous, variable length
- Character Set: All 128 ASCII characters
- Check Character: Mandatory modulo 103 check digit
- Quiet Zone: 10X minimum (X = narrow bar width)
- Density: 11 modules per character (plus 3 modules for stop pattern)
- Self-Checking: Yes
- Bidirectional Decoding: Yes
Our generator handles all these technical details automatically to ensure your barcodes are fully compliant with international standards and will scan reliably in any environment.