Choosing the right barcode format
- CODE128 — high density, supports all 128 ASCII characters. Default for shipping labels and asset tags.
- CODE39 — older standard, accepts uppercase letters, digits, and a few symbols. Common in industrial settings.
- EAN-13 — 13 digits. Required for retail products with an assigned GTIN. Last digit is a check digit (calculated automatically by the library).
- EAN-8 — 8-digit short version of EAN-13 for small packages.
- UPC — 12 digits, used for retail in North America.
- ITF-14 — 14 digits, used for shipping cartons and case-level tracking.
How to use the barcode generator
- Pick the format your downstream system expects.
- Type the value. Validation is enforced automatically — invalid inputs show an error.
- Adjust line color, height, and font size if you need to match a label template.
- Download the PNG or SVG.
Print quality tips
Always print barcodes in pure black on a white background — colored barcodes confuse many laser scanners. Maintain at least a 10× module quiet zone on either side. Test the actual print at the production size with the actual scanner before mass producing anything (especially EAN/UPC, where the check digit and X-dimension are strict).
FAQ
Are barcodes free to use? The symbology is free. EAN/UPC numbers themselves are issued by GS1 and require registration if you want them recognized in retail.
Can I encode a URL in a barcode? Use CODE128, but a QR code is far better for URLs.
Why does my EAN-13 fail? EAN-13 requires exactly 12 or 13 digits. If you supply 12, the library appends the check digit; if you supply 13, the last digit must be the correct check digit.
Is the value transmitted anywhere? No. Barcodes are rendered locally with JsBarcode running in your browser.