Online Barcode Generator
Create retail product barcodes, inventory SKU tags, and shipping labels in Code-128, EAN-13, and UPC-A formats.
Barcode Parameters
Complete Guide to 1D Barcode Symbologies, Check Digits & Retail Packaging
Linear (1D) barcodes represent alphanumeric product data using varying widths of parallel dark bars and light spaces. Scanned by laser and camera-based optical CCD readers at point-of-sale (POS) cash registers and automated logistics fulfillment conveyors, choosing the correct barcode standard ensures universal scanner compatibility.
Code 128 vs. Code 39 Symbology
Used for industrial warehousing, supply chains, and asset tagging:
- • Code 128: High density; encodes all 128 ASCII characters (Letters, numbers, control chars)
- • Code 39: Encodes uppercase letters (A-Z), digits (0-9), and symbols (-.$/+%*)
- • ITF-14: 14-digit numeric barcode printed directly on corrugated shipping cartons
GS1 Retail Standards (EAN-13 & UPC-A)
Global Trade Item Numbers (GTIN) printed on consumer retail products:
EAN-13: 13-digit standard for international retail (Europe, Asia, India, LATAM)
UPC-A: 12-digit standard for US & Canadian retail
Modulo 10 Check Digit: Last digit mathematically verifies scan accuracy
Linear 1D Barcode Standards & Specifications
| Symbology | Supported Character Set | Data Length | Industry Application |
|---|---|---|---|
| Code 128 | Full ASCII (128 characters) | Variable | E-commerce logistics, shipping labels, asset tags |
| EAN-13 | Numeric digits (0-9) | Fixed 13 Digits | Global supermarket retail products (GS1) |
| UPC-A | Numeric digits (0-9) | Fixed 12 Digits | North American Point of Sale (POS) retail |
| Code 39 | Alphanumeric (A-Z, 0-9, 7 symbols) | Variable | Automotive, military (DoD), badges |
| ITF-14 | Numeric digits (0-9) | Fixed 14 Digits | Outer cardboard master shipping cartons |
Frequently Asked Questions (FAQ)
What is the Modulo-10 checksum digit and how is it calculated?
EAN-13 and UPC-A use a weighted Modulo-10 formula on the trailing digit. Digits in odd positions are multiplied by 1 and digits in even positions by 3. The checksum makes the sum a multiple of 10, preventing misread scans.
Can I use this free barcode generator for products sold in retail stores?
To sell physical retail products globally in major retail stores (Amazon, Walmart, supermarkets), you must acquire an officially licensed GS1 Company Prefix. For internal warehouse inventory, asset tracking, or private label shipping, you can freely generate custom Code 128 / Code 39 barcodes.
Why should I export barcodes as SVG vector files?
SVG (Scalable Vector Graphics) preserves crisp infinite resolution at any DPI setting. When printing packaging labels, high vector edge contrast prevents blurring that could cause barcode scanner misreads.