About Code 39
Code 39 (also called Code 3 of 9) is one of the oldest alphanumeric barcodes. It's simple and very tolerant of poor printing, so it's still common in manufacturing, automotive parts, the US military's LOGMARS labels, healthcare wristbands and ID badges.
When to choose Code 39
- A customer, industry standard or existing scanner setup asks for it.
- You print with low-resolution equipment such as dot-matrix or old thermal printers.
- You only need capitals and numbers.
For new systems, Code 128 is usually the better choice: it's shorter and supports more characters.
Frequently asked questions
What characters does Code 39 support?
Capital letters A–Z, digits 0–9, space and the symbols - . $ / + %. We convert lower-case letters to capitals automatically.
Why is my Code 39 barcode so wide?
Code 39 uses more bars per character than Code 128, so it gets wide quickly. If your system allows it, Code 128 will be much more compact.
Does Code 39 need a check digit?
No, a check digit is optional in Code 39, and most systems don't use one. Scanners add the start/stop asterisks themselves, so don't type them.