Free Online Barcode Generator
Create high-resolution, custom 1D barcodes for retail, inventory, shipping, and packaging in seconds.
Barcode Settings
Barcode Preview
Barcode Information
Format: CODE128
Description: High-density linear barcode capable of encoding all 128 ASCII characters.
Common Uses: Any characters
What is a Barcode Generator?
A Barcode Generator is a specialized online utility designed to translate numerical, alphabetic, or alphanumeric data into standardized optical machine-readable linear patterns known as barcodes.
Barcodes consist of alternating parallel dark bars and light spaces of varying widths. When illuminated and scanned by an optical barcode scanner or smartphone camera, the reflected light sensor decodes the widths of the bars and spaces into digital binary sequences. This instantaneous data capture eliminates manual data entry errors, accelerates point-of-sale checkout speeds, streamlines supply chain logistics, and enables real-time inventory tracking across global industries.
Whether you are an e-commerce merchant creating Amazon FNSKU labels, a warehouse manager organizing SKU bins, a retail store owner tagging physical merchandise with UPC/EAN stickers, or a developer prototyping product tagging workflows, our free barcode generator delivers crisp, publication-ready vector outputs compliant with international GS1 and ISO standards.
Comprehensive Guide to Supported Barcode Symbologies
Selecting the correct barcode format depends on your industry requirements, the type of data you wish to encode (numeric vs. alphanumeric), and the space available on your label. Below is a breakdown of the formats supported by our generator:
1. CODE 128 (Universal Logistics & Shipping)
Character Set: Full 128 ASCII (Letters, Numbers, Symbols)
Code 128 is a compact, high-density linear symbology capable of encoding all 128 ASCII characters. It features three internal character sets (A, B, and C) allowing for maximum data efficiency. It is the gold standard for supply chain logistics, carton labeling (GS1-128), pharmaceutical distribution, and internal asset tracking.
2. EAN-13 & EAN-8 (International Retail)
Character Set: Numeric only (12-13 digits for EAN-13, 7-8 digits for EAN-8)
EAN (European Article Number / International Article Number) is the mandatory retail standard used outside North America. EAN-13 encodes a country code prefix, manufacturer code, product SKU, and a modulo-10 check digit. EAN-8 is a shortened variant optimized for small packages like confectionery and cosmetics.
3. UPC-A (North American Retail POS)
Character Set: Numeric only (11-12 digits)
Universal Product Code (UPC-A) is the ubiquitous 12-digit symbology scanned at grocery and retail checkouts throughout the United States and Canada. It is managed by GS1 US and guarantees unique identification for commercial consumer products.
4. CODE 39 (Industrial, Defense & Automotive)
Character Set: Alphanumeric (A-Z, 0-9, and 7 special characters: - . $ / + % SPACE)
Also known as 'Code 3 of 9', this self-checking symbology is widely deployed by the US Department of Defense (LOGMARS), healthcare badge identification, automotive manufacturing, and aerospace parts tracking due to its rugged reliability.
5. ITF-14 (Interleaved 2 of 5 for Corrugated Cartons)
Character Set: Numeric only (14 digits)
ITF-14 encodes a 14-digit Global Trade Item Number (GTIN) designed specifically for outer shipping boxes and corrugated master cartons. Its thick, wide bar patterns make it easy to scan even on uneven kraft cardboard surfaces.
6. Pharmacode & MSI Plessey
Character Set: Numeric only
Pharmacode is a single-track binary code specifically engineered for pharmaceutical packaging control to avoid packaging mix-ups. MSI (Plessey) is commonly used in retail shelf labeling, grocery inventory, and warehouse storage bins.
1D Barcode Formats Comparison Table
Use this reference table to choose the perfect barcode format for your application:
| Symbology | Data Type | Length | Check Digit | Primary Use Case |
|---|---|---|---|---|
| Code 128 | Full ASCII | Variable | Automatic (Modulo 103) | Logistics, Shipping, E-commerce, Inventory |
| EAN-13 | Numeric | 12 or 13 digits | Required (Modulo 10) | Global Supermarket & Retail POS |
| UPC-A | Numeric | 11 or 12 digits | Required (Modulo 10) | USA / Canada Retail Point of Sale |
| Code 39 | Alphanumeric (A-Z, 0-9) | Variable | Optional (Modulo 43) | Automotive, Defense, Industrial Badges |
| ITF-14 | Numeric | 14 digits | Required (Modulo 10) | Corrugated Master Shipping Cartons |
| Pharmacode | Numeric (3 to 131070) | 1 to 6 digits | None | Pharmaceutical Packaging Quality Control |
| MSI | Numeric | Variable | Automatic (Luhn 10) | Warehouse Shelving & Retail Storage |
How to Create Custom Barcodes in 4 Simple Steps
Select Symbology
Choose the format that fits your industry (e.g., Code 128 for inventory or EAN/UPC for retail products).
Enter Data Value
Input your product SKU, serial number, or item code. The tool validates input against format rules in real time.
Customize Visuals
Adjust bar width, height, margin quiet zones, font size, and custom foreground/background colors.
Download PNG
Click the download button to save a crisp, print-ready high-resolution PNG image immediately.
Best Practices for Printing & Flawless Barcode Scanning
- 1. Always Maintain Adequate Quiet Zones: Leave at least 10 times the width of the narrowest bar (or a minimum of 0.25 inches / 6mm) of pure white space on both the left and right ends of the barcode.
- 2. High Optical Contrast: The industry standard is solid black bars (#000000) on a pure white background (#ffffff). Never use red or yellow lines because red laser scanners cannot detect red wavelengths on white substrates.
- 3. Optimal Print Resolution (DPI): When printing labels via thermal transfer, direct thermal, laser, or inkjet printers, ensure a minimum resolution of 300 DPI to avoid fuzzy or bled edges.
- 4. Avoid Surface Glare & Curvature: If affixing labels to curved bottles or shrink-wrapped pallets, orient the barcode vertically (ladder style) rather than horizontally (picket fence style) to prevent distortion.
Industry Applications of Online Barcodes
📦 E-Commerce & Retail
Create Amazon FBA SKU labels, eBay listing stickers, Shopify product barcodes, and POS checkout tags to streamline sales transactions.
🏭 Warehousing & Supply Chain
Track pallet shipments, pallet bins, sorting conveyors, and storage racking with durable Code 128 and ITF-14 barcode labels.
🏥 Healthcare & Laboratories
Ensure error-free patient wristband identification, blood sample vial tracking, and pharmaceutical medication dispensing with Pharmacode.
Optical Scanner Compatibility & Modulo Check Digit Physics
Linear 1D barcodes function through alternating optical reflectance. Laser diodes typically emit visible red light at wavelengths between 630 nm and 670 nm. When the laser sweep traverses the white spaces between black bars, light is reflected back into a photodiode detector, converting optical pulses into electrical square waves. Because red light is reflected by red ink and absorbed by cyan, green, and black inks, attempting to print barcodes with red or pink bars on a white label causes optical scanners to perceive an unbroken white space, resulting in instant decode failures.
Furthermore, data reliability in industrial environments is guaranteed by mathematical check digits. EAN-13 and UPC-A utilize a Modulo 10 algorithm with alternating weights of 3 and 1, calculating a checksum that detects single-digit substitution errors with 100% mathematical accuracy and adjacent transposition errors with over 89% reliability. Code 128 employs a Modulo 103 checksum calculated across character weighting positions, ensuring that high-speed sorting conveyors scanning at 500 feet per minute never register corrupted payloads.
Frequently Asked Questions (FAQs)
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