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Free Online CODE 128B Barcode Generator

CODE128B Mode

Code 128 Set B covers printable ASCII from space through tilde, making it the subset of choice for mixed-case product codes and human-readable identifiers. Enter your text, validate against Set B rules, and download a barcode ready for labels or documents.

1. Enter barcode data

0 entries · Blank lines ignored · Duplicate values detected

2. Choose barcode settings

Barcode preview

Download settings

What is a CODE128B barcode?

CODE128B is the Code 128 subset for printable ASCII characters starting at the space character through tilde. It handles mixed-case strings, punctuation, and typical keyboard symbols efficiently without shifting into numeric Set C. Many shipping and document-tracking specs default to Set B when payloads are human-readable text rather than pure numbers.

Recommended generator settings

These defaults work well for preview and download. Adjust to match your label template or scanner tests.

Bar width Start at 2; increase only if scans fail at your print size
Height 100 px or taller for warehouse and logistics labels
Quiet zone Keep the default margin unless your spec defines a different quiet zone
Readable text Leave enabled when operators verify values manually
Output format PNG for design files; JPEG for documents and quick sharing

Practical examples

  • CT-001
  • item-alpha-9
  • Order#4421
  • batch-2026-q1

When should you use CODE128B?

  • Mixed-case SKU or order references on packing slips and pick lists
  • Document tracking barcodes that mirror human-readable titles
  • Internal IT asset labels with hostname-style identifiers
  • Workflows where label software exports explicitly require Subset B

Limitations and common mistakes

Pure numeric strings encode more compactly in CODE128C. Control characters below ASCII 32 require CODE128A instead.

  • Trimming quiet zones when cropping the image for a label layout.
  • Scaling the barcode unevenly so bar width ratios no longer match the generated image.

Related formats

CODE128B vs CODE128C

Format Best for Supported data Key difference
Code 128 Warehouse and inventory labels where the encoded value mixes letters and numbers Printable ASCII (codes 33–126) Letters, digits, and common punctuation within printable ASCII.
Code 128 Set C Long numeric shipment or container references on warehouse labels Digits 0–9 only Encodes digit pairs for maximum density on numeric-only data.
Code 128 Set A Label templates that explicitly require Code 128 Subset A encoding ASCII codes 0–95 (NUL through _) Function and control codes within ASCII 0–95 when your spec requires them.

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Printing and scanning notes

Printing

  • Use fonts for human-readable text that distinguish similar characters (0/O, 1/l).
  • Preserve quiet zones when labels are die-cut to size.
  • Avoid compressing bar height below your scanner vendor's minimum spec.

Scanning

  • Imager scanners generally read Set B symbols reliably at standard retail distances.
  • Confirm case sensitivity in your database matches the encoded string exactly.
  • Re-scan after laminating labels; glare can affect narrow Code 128 bars.

Frequently asked questions

Yes. Set B includes the full printable ASCII range from space through tilde, including lowercase.

This page locks encoding to Subset B. Standard CODE128 may switch to A or C for efficiency.

Any printable ASCII character from code 32 to 126 is accepted by the validator.

Yes, when SKUs mix letters and numbers in mixed case and your spec calls for Set B.

Control characters below ASCII 32 and DEL (127+) are not valid in Set B.

Yes. Enter one value per line for batch generation.

The encoder adds the standard Code 128 check character automatically.