About the Barcode Generator
The DwellixTools Barcode Generator is a free, high-performance web utility that allows you to instantly generate standard 1D linear barcodes. It operates entirely inside your local web browser, ensuring that whatever values you input are processed locally and never uploaded to any remote server, preserving absolute data privacy.
Whether you are designing labels for product inventory, creating retail tags, preparing shipping packages, or organizing book tags, this utility generates print-ready codes in real-time. You can choose from various barcode formats, customize dimensions (bar height and thickness), select text display options, adjust colors, and download the output in high-resolution PNG or vector SVG format.
Supported Barcode Formats
To ensure your barcode is readable by specific scanning equipment, choose the format that matches your industry:
1. Code 128 (Standard & Versatile)
Code 128 is a highly dense, high-performance format that supports the entire ASCII character set (letters, numbers, and special symbols). It is the standard barcode format for shipping containers, packaging labels, and general warehouse inventory tracking.
2. EAN-13 (International Retail)
The European Article Number (EAN-13) is used globally for labeling consumer goods at retail point-of-sale systems outside North America. It requires exactly 12 or 13 digits.
- Check Digit: If you enter 12 digits, this tool will automatically calculate and append the 13th check digit for you.
3. UPC-A (North American Retail)
The Universal Product Code (UPC-A) is the standard barcode format for retail products in the United States and Canada. It requires exactly 11 or 12 digits.
- Check Digit: If you enter 11 digits, this tool will automatically calculate and append the 12th check digit.
4. Code 39 (Industrial & Military)
Code 39 is a variable-length barcode that supports uppercase letters, numbers, and a few symbols (hyphen, period, space, dollar sign, slash, plus, percent). It is widely used in automotive, electronics, and military environments. It is less dense than Code 128 but highly readable.
5. Codabar (Libraries & Blood Banks)
Codabar is a self-checking barcode format that can encode numbers, symbols (-, $, :, /, ., +), and requires start/stop characters (A, B, C, or D). It is commonly used in library indexing, blood banks, and photo finishing envelopes.
Scanning & Printing Best Practices
- Verify Input Validation: Standard formats like EAN-13 and UPC-A will fail to scan if they contain characters other than digits or have incorrect lengths. Make sure to address validation warnings in the control panel.
- Maintain High Color Contrast: Standard barcode scanners expect black or very dark stripes on a pure white or light background. Avoid generating barcodes with light-colored lines or printing them on dark papers.
- Set Sufficient Height: Keep the barcode height tall enough (at least 0.5 inches or 13mm) so that linear laser scanners can cut across all bars cleanly at different scan angles.
- Allow Quiet Zones: Ensure there is a blank horizontal margin (quiet zone) on both the left and right sides of the barcode. Scanners need this blank space to recognize where the barcode pattern begins and ends.
Frequently Asked Questions (FAQ)
What is the difference between Code 128 and Code 39?
Code 128 is a modern, compact barcode format that can encode letters, numbers, and symbols, and it produces a much smaller physical barcode. Code 39 is an older industrial format that supports uppercase letters and numbers, but it requires much wider physical dimensions to house the same amount of data, making it less ideal for small labels.
Do barcodes require a check digit?
Yes, retail formats like EAN-13 and UPC-A require a mathematical check digit as the final number to verify scanning accuracy. DwellixTools automatically computes and appends this check digit for you if you enter 12 digits for EAN-13 or 11 digits for UPC-A, making it easier to generate valid retail codes.
Why won’t my barcode scan on a phone?
Smartphones scan barcodes using camera imaging. If a barcode has low contrast (e.g., light blue on white), is printed too small, or the input value violates the chosen format specification, mobile cameras and laser scanners will fail to decode it.