Zerdly

Barcode Generator

Generates downloadable barcode images in formats like Code128, EAN-13, UPC and Code39.

100% FreeRuns in your browserBasic
How to use this calculator

Barcode details

A generated barcode is not a registered GS1 number or ISBN — those come from GS1 or your ISBN agency.

Batch: many barcodes from a CSV

Header row with a value column, and optionally filename and label. Up to 1,000 rows. Every code uses the settings above: Code 128 (any text), 3 px modules, 50 modules high, text shown.

Result

Enter a value and press Generate.

Generated in your browser with bwip-js — nothing is uploaded.

How the method works

Keep the quiet zone clear
Illustrative method
Keep the quiet zone clearLeft: a QR symbol outline with its three finder patterns, surrounded by a dashed quiet-zone border four modules wide. Right: a barcode outline with a quiet zone of 11 modules on the left and 7 on the right, as EAN-13 requires.QR codequiet zone: 4 modulesEAN-13 barcode117modules clear · 95 dataSchematic outlines only — not scannable codes
QR codes need a clear margin of 4 modules on every side. Linear barcodes follow their symbology: EAN-13 needs 11 modules on the left and 7 on the right; Code 128 and Code 39 at least 10. Cropping, borders or text inside the margin can stop a code scanning. Both drawings are schematic, not scannable codes.

Print at 100% and test with the scanner that will read the code; this page does not decode codes back. Fixed example values for illustration — not your result.

How to use this calculator

  1. Pick a barcode type and enter the value. For EAN and UPC you can leave off the check digit and it is worked out for you.
  2. Choose the module width in pixels, bar height and print DPI to see the physical size.
  3. Press Generate, then download SVG (best for print) or PNG, and test-scan a printout. For many codes, open Batch: up to 1,000 CSV rows become a ZIP of SVGs with a manifest, or a print sheet; invalid rows are listed, never dropped.

How it works

Values are checked before encoding. A wrong EAN/UPC check digit is explained, and the corrected number is offered as a button — never applied silently. Codes are kept as text, so leading zeros stay.

bwip-js encodes the bars in your browser; the image is drawn from whole modules with the symbology's quiet zone (11 and 7 modules for EAN-13, 9 for UPC-A, 10 for Code 128 and Code 39) that no setting can trim.

A generated barcode is not a registered GS1 number or ISBN, and this page does not decode the symbol back, so it never shows "verified".

Worked example

EAN-13 4006381333931. Accepted (check digit 1). Typing …932 explains that the check digit should be 1 and offers 4006381333931. At 3 px per module the image is (11 + 95 + 7) × 3 = 339 px wide.

Common mistakes

  • Cropping the white space at either side — scanners need the quiet zone.
  • Scaling a PNG by a non-whole factor, which blurs the bars.
  • Using a made-up EAN on a retail product instead of a GS1-assigned number.

Tips

  • Runs entirely in your browser. Your input is not uploaded or stored.

Frequently asked questions

Why won't EAN-13 generate?

EAN/UPC need an exact number of digits and a valid check digit — the tool tells you the right one. Use Code 128 for free-form values.

Privacy?

Runs entirely in your browser. Your input is not uploaded or stored.

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Cite this tool

Zerdly. (2026). Barcode Generator. Retrieved from https://www.zerdly.com/tools/barcode-generator/

Tip: Enter any known values to calculate the remaining results.

Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.