Free 1D Barcode Generator
Create standard linear barcodes for retail, inventory tracking, shipping boxes, and product packaging. Generates sharp, scanner-compliant Code 128, EAN-13, UPC-A, and Code 39 vectors entirely in your browser.
Barcode Settings
Code 128 supports ASCII alphanumeric text, uppercase, lowercase, punctuation, and digits.
100% In-Browser Privacy: Barcode symbols, serial numbers, and SKUs are calculated locally using client-side JavaScript. No images or barcodes are sent to external servers.
1D Barcode Formats Comparison Matrix
| Symbology | Character Set | Length | Primary Use Case | Error Checking |
|---|---|---|---|---|
| Code 128 | Full 128 ASCII (Alphanumeric & Punctuation) | Variable | Shipping, Amazon FBA, logistics, serial numbers | Modulo 103 checksum |
| EAN-13 | Numeric (0–9) | Fixed 13 Digits | Global retail checkout, grocery, books (ISBN) | Modulo 10 check digit |
| UPC-A | Numeric (0–9) | Fixed 12 Digits | North American POS, retail supermarket items | Modulo 10 check digit |
| Code 39 | A–Z, 0–9, and 7 special characters (-, ., $, /, +, %, space) | Variable | Military (LOGMARS), automotive, warehouse asset tags | Optional Modulo 43 |
Barcode Printing & Scanner Readability Guidelines
| Dimension / Factor | Recommended Value | Scanning Impact |
|---|---|---|
| Quiet Zone (Margin) | At least 10x the narrow bar width (≥ 6.4mm) | Critical. Without adequate white space on both sides, laser scanners cannot detect start/stop codes. |
| Color Contrast | Dark bars (Black/Navy) on Light background (White/Yellow) | Never print red bars or white bars on red backgrounds; optical red lasers cannot detect red lines. |
| Minimum Bar Height | At least 15% of total barcode length or ≥ 20mm | Allows handheld laser scanners to swipe diagonally without missing bars. |
| Print Resolution | 300 DPI or vector SVG | Prevents ink bleed and fuzzy edges that create false reading errors. |
How to Generate and Print Scannable Barcodes
Choose Symbology
Select Code 128 for internal SKUs/shipping, EAN-13 for global retail, or UPC-A for US products.
Input Serial / SKU
Type or paste your alphanumeric code. Checksum digits are automatically calculated according to official GS1 rules.
Adjust Dimensions
Customize bar width, height, margins, and label font size to match your adhesive thermal sticker printer specifications.
Download Vector or Print
Export crisp vector SVG for Illustrator/packaging, high-DPI PNG, or print a live test sheet instantly.