What characters can a CODE-128B barcode encode?

CODE-128 Subset B supports all standard ASCII characters from code 32 to 127, including A–Z, a–z, 0–9, hyphens, slashes, and spaces.

Does the generator calculate the CODE-128 check digit automatically?

Yes. Our engine automatically computes and appends the mandatory Modulo-103 checksum bar pattern before the Stop character.

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Free CODE-128 Barcode Generator: Printable Vector Barcodes for Retail & SKU Labels

Reviewed by CompressPhoto Biometric & Imaging Lab • Updated & Verified: November 2026 • Standard Format: CODE-128B Linear Vector SVG & PNG (Standard Retail / Warehouse Label) — Target: Modulo-103 Checksum Verified

While 2D QR codes are built for smartphone cameras, retail checkout laser scanners, warehouse handheld terminals, and logistics conveyors rely on 1D linear barcodes. CODE-128 (specifically Subset B) is the most versatile alphanumeric barcode standard in the world, capable of encoding uppercase letters, lowercase letters, digits (0–9), and punctuation symbols.

Automatic Modulo-103 Checksum & Quiet-Zone Calibration

A CODE-128 barcode is more than just alternating vertical lines—every valid symbol requires a Start Code B pattern, weighted character values, a Modulo-103 Checksum symbol, and a 13-module Stop pattern.

Full ASCII 32–127 Support: Encode SKU strings like SKU-2026-094, serial numbers, or bin locations effortlessly.
Thermal & Laser Printer Ready: Crisp vertical bars with zero anti-aliasing blur ensure 100% first-pass reads on Zebra, Dymo, Brother, and standard laser sheet printers.
1-Click Exact-KB Compression Bridge: Need to upload a barcode image under 20 KB to a customs or inventory portal? Click "Send QR to Exact-KB (< 20KB)" right below the preview.

Frequently Asked Questions

What characters can a CODE-128B barcode encode?: CODE-128 Subset B supports all standard ASCII characters from code 32 to 127, including A–Z, a–z, 0–9, hyphens, slashes, and spaces.
Does the generator calculate the CODE-128 check digit automatically?: Yes. Our engine automatically computes and appends the mandatory Modulo-103 checksum bar pattern before the Stop character.