Understanding Barcodes: Types, Uses, and How They Work
Barcodes are everywhere — on every product you buy, every package shipped, every boarding pass and concert ticket. Despite being one of the most ubiquitous technologies in the world, few people understand how they work, the different types available, and when to use each one. This guide covers everything you need to know about barcodes in 2026.
A Brief History of Barcodes
The barcode was invented in 1951 by Norman Joseph Woodland and Bernard Silver, inspired by Morse code. Their original design used concentric circles rather than the parallel lines we know today. However, it wasn't until 1974 that the first product — a pack of Wrigley's Juicy Fruit gum — was scanned using a UPC barcode at a Marsh supermarket in Troy, Ohio.
Since then, barcodes have become the backbone of global commerce, logistics, healthcare, and manufacturing. Over 6 billion barcodes are scanned every day worldwide.
How Do Barcodes Work?
A barcode encodes data as a series of parallel lines (bars) of varying widths and spacings. A barcode scanner shines a light (usually a laser) on the barcode, and a sensor detects the pattern of reflected and absorbed light. This pattern is decoded into numbers or text.
The basic principle is simple:
- Dark bars absorb light → detected as "1"
- Light spaces reflect light → detected as "0"
- The width of bars and spaces encodes different characters
- Start and stop characters tell the scanner where the data begins and ends
- A check digit verifies the barcode was read correctly
Types of 1D Barcodes
One-dimensional (1D) barcodes are the traditional linear barcodes you see on products. Here are the most common types:
UPC-A (Universal Product Code)
The standard barcode for retail products in North America. It contains exactly 12 digits: a company prefix (assigned by GS1), a product number, and a check digit. Every product you buy at a US store has a UPC-A code.
EAN-13 (European Article Number)
The international version of UPC, used for retail products worldwide. It contains 13 digits and is compatible with UPC (a UPC is essentially an EAN-13 with a leading zero). If you sell products in Europe, Asia, or internationally, you need EAN-13.
Code 128
The most versatile 1D barcode format. Code 128 can encode all 128 ASCII characters, making it suitable for any text or numeric data. It's widely used in logistics, shipping labels, and inventory management. If you're not sure which format to use, Code 128 is usually the right choice.
Code 39
An older format that supports uppercase letters, numbers, and a few special characters. Common in automotive, defense, and healthcare industries. It's less space-efficient than Code 128 but has the advantage of being self-checking (no check digit required).
ITF-14 (Interleaved 2 of 5)
Used for marking cartons and pallets in the supply chain. ITF-14 encodes 14 digits and is designed to be printed on corrugated cardboard at lower print quality than retail packaging. If you see a barcode on a shipping box, it's probably ITF-14.
📊 Generate your own: Wootils Barcode Generator — create barcodes in Code 128, EAN-13, UPC-A, Code 39, and ITF formats. Download as PNG or SVG.
2D Barcodes: QR Codes and Beyond
Two-dimensional barcodes store data in both horizontal and vertical patterns, allowing them to encode much more information than 1D barcodes. The most common types are:
QR Codes (Quick Response)
Invented by Denso Wave in 1994 for the automotive industry, QR codes have become the most popular 2D barcode format. They can store up to 4,296 alphanumeric characters and can be read by any smartphone camera. QR codes are used for URLs, contact information, Wi-Fi passwords, payment systems, and more.
Need to create a QR code? Try the QR Code Generator on Wootils.
Data Matrix
A compact 2D format commonly used in electronics manufacturing, pharmaceutical packaging, and aerospace. Data Matrix codes are very small and can be printed on tiny components like circuit boards and medical devices.
PDF417
Used on driver's licenses, boarding passes, and government documents. PDF417 can store up to 1,800 characters and includes error correction, making it readable even when partially damaged.
Choosing the Right Barcode Format
| Use Case | Recommended Format | Why |
|---|---|---|
| Retail products (North America) | UPC-A | Required by US/Canadian retailers |
| Retail products (international) | EAN-13 | Global standard for retail |
| Shipping labels | Code 128 | Supports all characters, very compact |
| Outer carton marking | ITF-14 | Designed for rough surfaces |
| Internal inventory | Code 128 or Code 39 | Flexible, widely supported |
| URLs and marketing | QR Code | Readable by all smartphones |
| Tiny components | Data Matrix | Very compact, high density |
| Documents and IDs | PDF417 | High capacity with error correction |
Getting Official Barcodes for Products
If you're selling products at retail, you need official barcode numbers from GS1 (the global standards organization). The process works like this:
- Join GS1: Apply for a GS1 company prefix at gs1.org (or your local GS1 office)
- Assign numbers: Use your company prefix to create unique GTINs (Global Trade Item Numbers) for each product
- Generate barcodes: Use a barcode generator to create the barcode images
- Print on packaging: Ensure proper size, placement, and quiet zones (whitespace around the barcode)
For internal use (inventory, asset tracking), you don't need GS1 — you can use any format and numbering scheme.
Barcode Best Practices
- Quiet zones: Leave at least 10x the narrowest bar width as blank space on each side of the barcode
- Contrast: Use dark bars on a light background. Black on white is best. Avoid red, orange, or yellow backgrounds (scanners use red light)
- Size: UPC/EAN barcodes should be at least 80% of the nominal size (1.47" × 1.02" for UPC-A at 100%)
- Placement: Place barcodes on flat surfaces, not on curves or seams
- Test: Always test your barcodes with a scanner before mass printing
The Future of Barcodes
Despite predictions of obsolescence, barcodes continue to evolve. GS1 is developing "next-generation" barcodes that can carry more data and link to digital product information. RFID (Radio-Frequency Identification) tags are replacing barcodes in some supply chain applications, but the simplicity, low cost, and universal compatibility of printed barcodes ensure they'll remain relevant for decades to come.
Conclusion
Barcodes are a foundational technology that powers global commerce and logistics. Whether you need to create product labels, shipping barcodes, or inventory tags, understanding the different formats and their appropriate uses helps you make the right choice. For quick barcode generation, try the Barcode Generator — it supports all major formats and runs entirely in your browser.