Barcode Label Maker

How to use

1. Pick a symbology and enter the text. Code 39 is the default in this package (Code 128 is not drawn — see Limitations). Use EAN-13, EAN-8 or UPC-A only for codes that already belong to a product, and check the check digit the tool calculates.
2. Set the size in millimetres. X-dimension, bar height and quiet zone change the printed size measurably. Keep the quiet zone intact; a cropped quiet zone is a common reason a code will not scan.
3. For sheets, pick a label size or a custom layout. Rows, columns, margins and gaps decide how many labels fit on a page and where each one lands. For bulk work, upload a CSV of SKU, text and quantity; leading zeros are kept exactly as typed.
4. Print at 100% / Actual Size and measure one label with a ruler. “Fit to page” rescales the sheet and breaks the millimetre accuracy. If the ruler does not match, do not use that print.

Worked example

Load sample fills Code 39 with the fictional SKU SKU-1042. Code 39 allows only uppercase letters, digits, space and the symbols minus, dot, dollar, slash, plus and percent, so the sample is valid as typed. The tool builds the bar pattern from the published Code 39 table, with a start and stop asterisk, and the SVG export is made of vector rectangles, not a stretched raster image. For a retail example, the sample EAN-13 code 5901234123457 has a check digit of 7, calculated from its first twelve digits; entering the same twelve digits with a wrong final digit is rejected with the expected digit shown, not silently corrected.

Limitations

This tool does not assign GS1 numbers, and a code made here with a fictional or internal number is not a retail product code. Real retail codes must come from GS1. It cannot guarantee that a retailer's scanner will accept a code, and it cannot make a “Fit to page” print accurate — only a 100% print is accurate. Data Matrix is not offered in Wave 1, because no MIT or Apache encoder was verified in this build; the page states that removal plainly instead of promising a format it cannot produce. Code 128 is not drawn in this package: the JsBarcode library it was delegated to is not bundled here, so choosing Code 128 shows that limit plainly instead of drawing an unverified code. Code 39, EAN-13, EAN-8, UPC-A and ITF-14 are drawn from the built-in tables, and a printed test page at 100% scale is part of the acceptance check for every sheet layout.

How a scanner reads a label

A barcode scanner does not read numbers as a person does. It measures the widths of bars and spaces, in order, and matches that pattern against the symbology it expects. That is why exact size, contrast and quiet zone matter more than how the code looks on screen. A code stretched wider than it is tall, printed with bars that bleed into each other, or placed so close to text that the scanner cannot tell where the code ends, will fail even though the data was correct. The scanner also checks the check digit, where the symbology has one, and rejects a code whose check digit does not match, which is why the tool shows the calculated digit instead of hiding it. For sheets, the same logic applies at page level: if one label is misaligned, the next label on the sheet may also be cut or clipped, so measuring the first printed sheet with a ruler, and scanning one label from each row, catches layout errors before a whole batch is printed.

Frequently asked questions