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Codabar Barcode Generator

Codabar is an older numeric barcode that is still found on library cards, lab sample tubes and legacy tracking systems. Enter your number, choose the start and stop letters your system expects, and export a clean vector label.

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Where Codabar is used

Codabar was developed in the early 1970s and became popular because it could be printed with simple equipment, including dot-matrix printers. It was historically used by libraries, blood banks and on FedEx airbills. Many blood banks have moved to ISBT 128, and carriers use other codes today, but libraries and some laboratories and photo labs still rely on Codabar. It is known under several names, including NW-7, USD-4 and 2 of 7 code, and is described in ANSI/AIM BC3.

Character set and structure

  • Data characters: digits 0–9 and the symbols - $ : / . +.
  • Start and stop characters: A, B, C or D (some systems print them as T, N, * and E). They frame the data and can carry meaning in some applications, for example a library system expecting A...A.
  • Each character is made of four bars and three spaces and is separated by an intercharacter gap, so Codabar is a discrete symbology.
  • There is no mandatory check digit; some systems apply their own, such as a mod-16 or Luhn digit on library numbers.

Printing tips

Codabar is low density, so keep data short. Use a wide-to-narrow ratio of about 2.5:1 to 3:1, a quiet zone of at least 10X and a bar height of at least 6 mm. When replacing worn library or sample labels, match the start and stop characters and any check digit used in the original system, or the scanner may reject the code. Print dark bars on light, non-glossy labels.

How to make it

  1. Choose Codabar in the barcode generator.
  2. Enter the data using digits and allowed symbols only.
  3. Pick the start and stop characters (A, B, C or D) that your system uses.
  4. Export SVG, PDF or PNG, or print a run of labels from a CSV list.
  5. Scan a test label with your existing scanner.

Frequently asked questions

Should I use Codabar for a new project?

Usually not. Code 128 is more compact and widely supported. Use Codabar when an existing system requires it.

Why does my scanner show letters around the number?

It is transmitting the start and stop characters. Most scanners can be configured to strip them.

Can Codabar encode letters?

Only A–D as start and stop characters, not as data.