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Universal high-density barcode supporting all 128 ASCII characters.
What is Code 128 Barcode?
Universal high-density barcode supporting all 128 ASCII characters. Defined under standard ISO/IEC 15417, Code 128 is engineered for fast, reliable optical scanning across industrial and commercial environments.
| Specification | Details |
|---|
| Standard Symbology | Code 128 (ISO/IEC 15417) |
| Character Set | Full 128 ASCII character set (A-Z, a-z, 0-9, and symbols) |
| Checksum Algorithm | Modulo 103 check digit (automatically calculated) |
| Quiet Zone Margin | Minimum 10 times the narrow bar width (X-dimension) on both left and right sides |
| Processing Mode | 100% Client-Side In-Browser (Zero Server Logs) |
✅ Key Advantages
- •High data density with variable length
- •Supports numbers, uppercase letters, lowercase letters, and punctuation
- •Three auto-switching code sets (A, B, C) for maximum compression
- •Universally recognized by virtually all 1D barcode scanners
📦 Common Use Cases
- •Logistics, carton tracking, and container labeling
- •Amazon FNSKU inventory barcode labels
- •Internal asset tagging and warehouse inventory management
- •Healthcare and medication sample tracking
Frequently Asked Questions
What is Code 128 barcode?
Code 128 is a high-density, variable-length linear (1D) barcode symbology defined by ISO/IEC 15417. It can encode all 128 ASCII characters including uppercase letters, lowercase letters, numbers, and punctuation.
How does Code 128 check digit calculation work?
Code 128 uses a Modulo 103 checksum. Each character is assigned a weighted value multiplied by its position index in the string. The sum is calculated modulo 103, and the corresponding check character is appended before the stop pattern.
Can I use Code 128 for Amazon FNSKU labels?
Yes! Amazon FNSKU barcodes use Code 128-A or Code 128-B format. MakeMyBarcode generates 100% compliant Code 128 barcodes for Amazon seller inventory.
What is the difference between Code 128 and Code 39?
Code 128 is much more compact and data-dense than Code 39. Code 128 supports lowercase letters and full ASCII with a built-in Modulo 103 checksum, whereas standard Code 39 supports only uppercase letters and digits.
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