​​Understanding 1D Barcodes like UPC-A and UPC-E​

​​One-dimensional linear barcodes are the familiar codes seen on everyday items like groceries, packaged goods, household products, and shipping labels. Information is stored in bars and spaces, with some codes holding only numbers and others encoding letters and additional characters as well.  

​Scanners read these patterns left to right and convert them into data. Laser scanners sweep a beam, CCD scanners use sensor arrays, and linear imagers capture and decode the barcode digitally. The height and width of 1D barcodes can vary depending on the space available on a product and the scanning environment.​ 

The UPC-A and UPC-E barcodes are the most common codes in the United States, and the most widely recognized. They’re used mostly in retail settings, such as grocery stores. UPC-A was developed by the Uniform Grocery Product Code Council, in conjunction with IBM, and has been in use since 1974. The first UPC barcode ever scanned was a pack of Wrigley's Juicy Fruit chewing gum. The pack later went on display in the Smithsonian.

The size of the code is the only real difference between the two: UPC-E is a smaller version of UPC-A, which makes it better suited for small packages and items.  

Specifications: A UPC-A barcode consists of 12 digits, while a UPC-code has 6. Each digit is represented by a uniquely identifiable pattern of two bars and two spaces of varying width.

They begin with a single number that classifies the code as one of several categories: a regular product, a weighed item, pharmaceuticals, coupons, etc. That’s followed by a number that represents the manufacturer and another for the product.  

The last number in the code is a check digit. A mathematical formula computes the first 5 or 11 digits together in a way that generates a single digit. If the check digit doesn't match the one generated by the formula, that immediately flags that there's an error.

The reduced size of the UPC-E omits extra zeros that come between the manufacturer number and the product number in a full-sized code.

Disadvantages: It's only a numeric code and cannot encode letters. Additionally, the fixed length limits the amount of information that can be encoded, making it fine for supermarkets, but inadequate for communicating more detailed information.

Advantages: UPC-A barcodes are simple, short, popular, and can be read by just about any standard barcode reader. In addition, the check digit guards against accidental errors, especially when entering in the code by hand. Advantages: Its condensed size allows it to fit on smaller packages. It also has a check digit, to ensure accuracy when typing a code in by hand.

Disadvantages: The 12 digit system of a UPC-A barcode provides for small, limited encoding, which makes it ideal for supermarket and retail use, but less suited for other scanning and identification purposes. 

Industry standards guarantee 1D barcodes are correct, scannable, and universally readable across retailers, warehouses, and logistics networks. Adhering to these standards helps prevent errors, reduces mis-scans, and maintains consistent performance worldwide. This is key to keeping supply chains and point-of-sale systems running smoothly. 

Industry standards:

GS1 • AIM-Global • ISO/IEC • MIL-STD-1189 • ANSI • HIBCC • US FDA

Other common 1D linear barcode types include:

• Code 39: Versatile alphanumeric barcode widely used in inventory and asset tracking.
• Code 128: High-density barcode for fast, reliable data encoding across industries.
• EAN 13: The global standard for retail product identification and scanning.
• GS1 DataBar expanded: Encodes more information in a small space for fresh foods and retail items.
• GS1 omnidirectional: Scannable from any angle, perfect for high-speed retail checkout.
• Interleaved 2 of 5: Compact numeric barcode ideal for logistics and warehouse labeling.

Choosing the right type for your products or operations ensures accurate scanning, efficient tracking, and seamless workflow integration.