What is Code 39 Barcode?
Code 39 (also known as Code 3 of 9, Alpha39, or USS Code 39) is an alphanumeric barcode standard that encodes 43 characters including uppercase letters (A-Z), numbers (0-9), and special characters (-, ., $, /, +, %, space). It's one of the most widely used barcode standards, especially in defense, healthcare, automotive, and manufacturing industries. Code 39 is defined by ISO/IEC 16388:2023 international standard.
Why Use Code 39 Barcodes?
Industry Standard
Widely adopted across defense (LOGMARS), healthcare (HIBCC), automotive (AIAG), and manufacturing industries.
Alphanumeric Support
Supports both letters and numbers, making it versatile for product codes, serial numbers, and identifiers.
Self-Checking
Built-in self-checking design helps prevent scanning errors. Optional Mod 43 checksum available for enhanced accuracy.
Universal Compatibility
Supported by virtually all barcode scanners and systems worldwide, ensuring broad compatibility.
How to Use Code 39 Barcodes
- Enter Your Data: Type the alphanumeric data you want to encode. Code 39 supports uppercase letters (A-Z), numbers (0-9), and special characters (-, ., $, /, +, %, space).
- Customize Appearance: Adjust width scale, height, foreground color, and background color to match your design requirements.
- Display Text (Optional): Enable "Display text value" to show the encoded data below the barcode for human readability.
- Test & Download: Preview your barcode, test it with a scanner, then download in SVG, PNG, JPG, or WEBP format for printing or digital use.
Frequently Asked Questions
Code 39 encodes 43 characters: uppercase letters A-Z, numbers 0-9, and special characters: space, hyphen (-), period (.), dollar sign ($), slash (/), plus (+), and percent (%). It does not support lowercase letters.
Code 39+ (C39+) includes a Mod 43 checksum digit for error detection. The checksum helps verify data integrity during scanning, making it more reliable for critical applications. Standard Code 39 is self-checking but doesn't include a checksum.
Code 39 is used in defense (US Department of Defense LOGMARS), healthcare (HIBCC device identification), automotive (AIAG standards), manufacturing, electronics, postal services, asset tracking, and inventory management.
Code 39 has no fixed maximum length, but practical limits depend on scanner capabilities and print quality. Very long barcodes may be difficult to scan. For best results, keep barcodes under 20-30 characters when possible.
Yes! Code 39 is one of the most universally supported barcode formats. Virtually all barcode scanners, including handheld, fixed-mount, and mobile phone scanners, can read Code 39 barcodes.
Code 39 Extended (C39E) supports the full ASCII character set including lowercase letters and additional special characters by using character pairs. Standard Code 39 only supports 43 characters (uppercase, numbers, and limited special characters).
Quiet zones are blank spaces required before and after the barcode. Code 39 requires minimum quiet zones of 10 times the narrowest element width or 0.10 inch, whichever is larger. These zones help scanners identify where the barcode starts and ends.
Yes! Code 39 is excellent for product labels, especially in industries like automotive, defense, and manufacturing. However, for retail products, EAN-13 or UPC-A are more commonly used standards.
For best scanning results, print Code 39 barcodes at 300 DPI or higher. The barcode should be printed clearly with good contrast between bars and spaces. Avoid low-resolution printing that may cause scanning issues.
Yes! If you're logged in, you can edit saved Code 39 barcodes and update the encoded data, colors, size, or other settings. The barcode will be regenerated with the new information.
