Barcode Generator

How to generate a barcode

1. Choose the barcode format, for example CODE128 for general use or EAN-13 for retail.
2. Type the number or text to encode.
3. Check the live preview to confirm the barcode renders correctly.
4. Download the barcode image.
5. Print it on your label or packaging and test it with a scanner.

Which barcode format should you choose?

CODE128 is the safe default for internal use: it encodes letters, numbers and symbols compactly, and virtually every scanner reads it. Use it for asset tags, inventory bins, membership cards and shipping references. EAN-13 is the 13-digit format on retail products in most of the world (UPC-A is its 12-digit US cousin); it encodes numbers only and includes a check digit.

One honest caveat about retail: generating an EAN-13 image is free, but the number inside it must be a legitimate one. To sell in stores or on marketplaces, the digits are issued by GS1; you cannot invent them. For anything inside your own business, use any numbering scheme you like with CODE128.

How a barcode encodes your data

A 1D barcode represents your characters as a pattern of parallel bars and spaces of varying width. The scanner shines light across the code, reads the reflected pattern, and decodes it back into the original text or number using the rules of the chosen symbology. Different formats use different rule sets, which is why a scanner has to recognise the symbology to read it correctly.

This barcode generator draws that pattern for you the moment you type. The critical point is that the data must be valid for the symbology you picked: EAN-13 accepts only digits of a fixed length, while CODE128 accepts a much wider character set. Feed a format data it cannot represent and the code will not render, which is the tool telling you the input does not fit.

Check digits and valid input

Retail symbologies like EAN-13 and UPC-A carry a check digit, a final number calculated from the others so a scanner can catch a misread. Enter 12 digits for EAN-13 and the correct 13th can be computed for you; enter all 13 and they must already agree, or the code is invalid. This is a built-in guard against typos, not an optional extra.

CODE128 has its own internal checks handled automatically, so you are free to encode plain product names, location codes or serials without worrying about a manual formula. The practical rule is simple: match your data to the format's requirements, digits and length for retail codes, near-anything for CODE128, and the barcode renders cleanly.

Made in your browser, codes stay private

Every barcode here is drawn by JavaScript running on your device. The product codes, asset numbers and serials you type are never uploaded, logged or stored on a server, so your internal numbering stays confidential even when it hints at stock levels, suppliers or naming conventions you would rather not publish.

Because there is no server round-trip, the preview updates instantly and the tool keeps working offline once loaded. Generate and download as many labels as a job needs without an account, a fee, or a watermark stamped across your artwork.

Where barcodes still beat everything else

For fast, repetitive scanning, 1D barcodes remain unbeaten on cost and speed. Shops label products for the till, warehouses tag bins and pallets for picking, libraries mark books, offices track laptops and equipment, and events print entry tickets. A short code on the label points into your own database, where the real detail lives, so the label itself stays small and cheap to print.

CODE128 covers almost all of these internal jobs because it packs letters and numbers densely and reads reliably on handheld laser and imager scanners. Reserve EAN-13 and UPC-A for goods that will cross a retail checkout or list on a marketplace, where the standard retail number is what the systems expect to see.

Printing barcodes that scan first time

Print quality decides whether a scanner reads a code in one pass or not at all. Keep high contrast, ideally solid black bars on a white background, and never scale the image in a way that blurs or stretches the bars, since the scanner reads their relative widths. Leave the quiet zone, the blank margin on each side, because the scanner uses it to find where the code starts and ends.

Size the code for how it will be scanned and printed: too small and a low-resolution printer smears the narrow bars together. Always run one test label through your actual scanner before committing to a large batch, and check it at the real print size rather than zoomed in on screen.

Common barcode mistakes to avoid

The usual retail slip-up is inventing an EAN or UPC number and expecting it to work in stores; those digits must come from GS1 to be valid at tills and on marketplaces. Related errors are feeding EAN-13 the wrong length or any letters, or supplying a check digit that does not match, all of which stop the code from rendering. When a retail format refuses your data, CODE128 is usually the right choice for internal use.

The other pitfalls are physical: printing too small, low contrast, or cropping the quiet zone, each of which can turn a technically valid code into one no scanner will read. Test before you print in volume, and keep the encoded data as short as the task allows, since shorter codes print larger bars and scan more forgivingly.

Frequently asked questions

Related tools