What is the difference between Code 128 and UPC-A?

Code 128 can encode letters, numbers, and symbols for internal inventory; UPC-A is restricted to 12 numbers for standard consumer retail checkout.

Can I print barcodes on standard thermal label printers?

Yes. Downloaded PNG and SVG images are compatible with thermal label software (Zebra, Brother, Dymo) and graphic design tools.

Are my serial numbers stored or shared?

No. All barcode generation logic executes locally inside browser memory; zero product codes are sent over the network.

Free & Private Online Browser Utility

Barcode Generator: Code 128, EAN & UPC Free

Generate high-resolution 1D linear barcodes directly in your browser using standard canvas rendering algorithms. Create Code 128, EAN-13, UPC-A, and Code 39 symbologies with customizable bar width, height, quiet zones, and human-readable text labels. You can download the generated barcode as a transparent PNG or SVG vector graphic for retail inventory, packaging labels, and asset tracking without uploading private serial numbers to external servers.

How to use

Step 1: Select Barcode Symbology

Choose your format: Code 128 (alphanumeric logistics), EAN-13 (global retail), UPC-A (North American retail), or Code 39.
Step 2: Input Data Value

Enter your product SKU, serial number, or retail GTIN string. The preview renders in real time.
Step 3: Download Image or Vector

Select PNG or SVG export and download your barcode ready for thermal label printers or graphic layouts.

Options explained

Code 128 Symbology

High-density barcode encoding all 128 ASCII characters with check digit verification.

When to use: Use for shipping cartons, logistics labels, and internal asset tags.

EAN-13 & UPC-A

Numeric retail barcodes required for consumer checkout scanners worldwide.

When to use: Use when packaging retail products assigned an official GS1 company prefix.

Human-Readable Text

Displays the encoded string below the vertical bars in clean monospace typography.

When to use: Use so warehouse staff can manually key in numbers if a scanner lens is smudged.

Worked example

Input: Symbology: Code 128, Data: 'TOOLVERVE-103', Bar width: 2px

Output: Linear barcode pattern rendered at 300x120 pixels with human-readable text

Generated using standard character parity patterns and modulo 103 checksum calculation.

Tips & limits

Maintain white quiet zones (blank space) on both sides of the barcode so optical scanners detect boundary markers.
Vector SVG export allows bars to remain sharp when scaled on high-DPI packaging printers.
UPC-A requires exactly 11 or 12 numeric digits; EAN-13 requires 12 or 13 numeric digits.

Common problems

Barcode scanner fails to read printed output: Verify adequate contrast between dark bars and light background, and ensure quiet zones were not cropped.
Invalid character error for UPC or EAN: UPC and EAN formats accept numeric digits only; use Code 128 if your SKU contains letters or hyphens.

Frequently Asked Questions (FAQ)

What is the difference between Code 128 and UPC-A?: Code 128 can encode letters, numbers, and symbols for internal inventory; UPC-A is restricted to 12 numbers for standard consumer retail checkout.
Can I print barcodes on standard thermal label printers?: Yes. Downloaded PNG and SVG images are compatible with thermal label software (Zebra, Brother, Dymo) and graphic design tools.
Are my serial numbers stored or shared?: No. All barcode generation logic executes locally inside browser memory; zero product codes are sent over the network.

How to use

Step 1: Select Barcode Symbology

Step 2: Input Data Value

Step 3: Download Image or Vector