What is GS1-128 Barcode?
GS1 global standard barcode with Application Identifiers (AIs) for shipping containers, SSCC, batch numbers, and expiration dates. Defined under standard GS1 General Specifications / ISO/IEC 15417, GS1-128 is engineered for fast, reliable optical scanning across industrial and commercial environments.
| Specification | Details |
|---|
| Standard Symbology | GS1-128 (GS1 General Specifications / ISO/IEC 15417) |
| Character Set | GS1 Application Identifiers and alphanumeric data |
| Checksum Algorithm | Modulo 103 check digit plus GS1 FNC1 start character |
| Quiet Zone Margin | 10 times the X-dimension on left and right |
| Processing Mode | 100% Client-Side In-Browser (Zero Server Logs) |
📐Engineering Specification
Deep-Dive: How GS1-128 Encodes Data
GS1-128 (formerly known as UCC/EAN-128) is a specialized application of the Code 128 symbology governed by GS1 General Specifications. While standard Code 128 can encode arbitrary raw text, GS1-128 is strictly structured using standardized GS1 Application Identifiers (AIs). It enables supply chain partners to communicate complex logistics data—such as pallet Serial Shipping Container Codes (SSCC-18), batch numbers, production dates, expiry dates, net weights, and purchase order numbers—in a universally machine-readable format.
⚙️ Application Identifiers (AIs) & FNC1 Flag Character
The defining characteristic of GS1-128 is its structured data syntax:
- ›Function 1 (FNC1) Character: A mandatory invisible flag placed immediately after the start character that instructs the scanner that the following data adheres strictly to GS1 Application Identifier standards.
- ›Application Identifiers (AIs): Two-, three-, or four-digit prefixes enclosed in parentheses in human-readable text that define the meaning and format of following data.
- ›Common AIs: (00) SSCC-18 Pallet Identifier, (01) GTIN Trade Item Number, (10) Batch/Lot Number, (15) Best Before Date, (17) Expiration Date, (310x) Net Weight in Kilograms, (400) Customer PO Number.
- ›Variable Length Separators: When combining variable-length data fields, an FNC1 character is inserted between elements to signal the end of one field and the start of the next AI.
🔬 Physical Barcode Anatomy & Zone Breakdown
Quiet Zone
Minimum 10 times the X-dimension of clear lateral margin.
Start Character (A, B, or C)
Initiates Code 128 symbology stream.
FNC1 Character
Crucial GS1 identifier distinguishing GS1-128 from proprietary Code 128.
Application Identifiers & Data
Chained sequence of standardized GS1 logistical attributes.
Modulo 103 Checksum
Integrity validation character.
Stop Character & Quiet Zone
Completes optical reading cycle.
🖨️ Production & Printing Best Practices
- ✔Parentheses around Application Identifiers (e.g. "(01)") are strictly for human-readable presentation and must NOT be encoded into the barcode bars themselves.
- ✔Keep overall barcode length under 48 data characters (including AIs) and maximum physical length under 165 mm (6.5 inches) including quiet zones to fit standard shipping labels.
- ✔For pallet logistics labels (SSCC), print at an X-dimension between 0.495 mm and 1.016 mm and place the label on two adjacent sides of the pallet.
📷Optical Scanner Compatibility: Supported by all modern GS1-certified 1D and 2D industrial barcode scanners, ERP handheld terminals (SAP, Oracle, NetSuite), and automated warehouse sorters.
⚠️ Official Retail & GS1 Compliance Notice
MakeMyBarcode generates standard-compliant, high-resolution barcode images for free. However, MakeMyBarcode does not assign official company prefixes. If you are selling products in commercial retail stores (Amazon, Walmart, Target), you must license your official company prefix directly from GS1.