Code 39

Code 39 (also known as Code 3 of 9, Alpha39 or Barcode39) is a technical standard developed by Intermec Corporation in 1974 and used to encode information in the form of a barcode.

The code 39 standard defines 43 characters. These are:

• Upper-case letters A to Z, although it is also possible to encode low-case characters.
• Numbers 0 to 9.
• Special characters -, ., $, /, +, %, and the space character.
• The special character *, which is used as a delimiter at the beginning and end of the encoded information.

Each encoded character is composed of 9 elements: four spaces and five bars. Of these 9 elements, 3 are wide (for a binary value of 1) and 6 are narrow (for a binary value of 0).

Because of the amount of characters it can encode, code 39 can be used to encode most of the information required in industrial applications. Moreover, barcodes created with the code 39 standards can be read by most of the barcode readers in the market.

As a drawback, the more information is encoded using code 39, the longer the code becomes. As a result, barcodes created with code 39 are not suitable for small labels. Alternative solutions such as a QR code or a data matrix code should therefore be preferred.

Creating a barcode using the code 39 standard is fairly simple. The only thing required is a label software that supports the standard.

In practice, the information that must be encoded is entered in a field and the software automatically generates the respective barcode, which can then be printed and applied.

The two main differences between code 39 and code 128 is that the latter is capable of encoding more characters and has a higher density, which means it can be printed more clearly.