Barcode Generator

Use this Barcode Generator for inventory labels or existing retail identifiers, then download SVG or PNG output.

Barcode Preview

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Enter values to begin.

Clear controls

Review inputs and results

Transparent methods

Understand the output

Works on any device

Mobile, tablet or desktop

How to Use the Barcode Generator

Select Code 128, Code 39, EAN-13 or UPC-A and enter compatible data. Retail formats require the complete code including its correct check digit. Set narrow-bar module width and bar height in pixels, toggle readable text, and download or print the result. Reset restores the sample.

Formula and Explanation

Retail check digit = (10 − weighted payload sum mod 10) mod 10
From the rightmost payload digit, alternate weights 3 and 1.

Code 128 uses compact variable-length symbols and a built-in symbol checksum. This interface accepts printable ASCII. Code 39 accepts uppercase letters, numbers, space and - . $ / + %, with no optional Mod 43 checksum added. EAN-13 requires 13 digits and UPC-A requires 12; the final digit is validated rather than invented. A white quiet zone is preserved around the black bars.

Generating a valid symbol does not assign a GS1 identifier, prove ownership or register a retail product. Scanner support depends on format, print quality and physical dimensions. Pixel controls are not a certification of retail print specifications. Do not crop quiet zones or stretch the image; verify the final printed label with your scanner. Very wide barcodes scroll in the preview instead of being squeezed.

Worked Example

EAN-13 payload 400638133393 has weighted sum 89, so the check digit is 1: enter 4006381333931. UPC-A 036000291452 is a valid 12-digit example. Code 128 can encode Jolbox-123; Code 39 can encode JOLBOX-123.

Frequently Asked Questions

Can I enter only an EAN or UPC payload?

No. Enter all 13 EAN-13 digits or all 12 UPC-A digits, including the check digit. Invalid lengths and check digits stop generation rather than being silently corrected.

Which format supports ordinary text?

Code 128 accepts printable ASCII text here. Code 39 is limited to uppercase letters, digits, spaces and its listed punctuation; lowercase, asterisk and Unicode are rejected.

What do width and height mean?

Width is the narrowest module in whole pixels, from 1 to 5; total symbol width depends on encoded data. Height controls bars from 30 to 300 pixels. Quiet-zone margins remain present.

Is a downloaded barcode ready for every store?

No. A syntactically valid barcode is not a GS1 assignment or a guarantee of scanner compatibility. Confirm identifier rights, retailer rules and final physical print quality.