How to make a barcode
- Pick the barcode type. Not sure? EAN-13 or UPC-A for products in shops, ITF-14 for cartons, Code 128 for everything internal.
- Type the number or text. For EAN, UPC and ITF-14, leave off the last digit: the check digit is calculated and added. If you type the full number, a wrong check digit is caught and the right one is shown.
- Adjust the size, text, colours and rotation. The line under the preview reads the barcode back after every change, drawn exactly as you will download it, and shows what a scanner gets.
- Download an SVG, a PNG at your printer’s resolution or a PDF, or print a sheet of labels.
For many barcodes, switch to Many (batch) and paste a column from a spreadsheet: one value per line, or CSV with the value, a line of text for the label (a product name or price) and the number of copies. Fill a numbered sequence makes asset tags such as ASSET-0001 to ASSET-0500. Every barcode in the list is test-read, and lines with mistakes are listed with their line number.
Where retail barcode numbers come from
A barcode is only the drawing; the number inside decides whether a shop can use it. The numbers in EAN-13, UPC-A, EAN-8 and ITF-14 barcodes are GTINs (Global Trade Item Numbers), and they must be unique worldwide. You can’t make one up: it starts with a company prefix licensed by GS1, the standards body that runs the system. Join the GS1 organization in your country, or in the US buy a single GTIN from GS1 US for a one-off product. Numbers sold cheaply by resellers are usually recycled from another company’s prefix, and retailers and marketplaces, Amazon included, check listings against the GS1 database and reject them.
Some numbers don’t need a licence because they never leave your business. Numbers starting with 02, 04 or 2 are restricted circulation numbers, used for in-store labels and variable-weight items, and the prefix 952 is reserved for examples (the samples on this page use it). For stock, bins and assets inside your company, Code 128 with your own codes is simpler and holds letters too.
Choosing the barcode type
- EAN-13 and UPC-A carry the same GTIN at the checkout; UPC-A is the 12-digit North American form. UPC-E squeezes some UPC numbers starting with 0 into six digits for small packs; the generator converts a UPC-A number when its zeros allow it. EAN-8 is for very small items and needs its own number from GS1.
- ITF-14 marks cartons and cases. The thick bearer bars around it stop a scanner from reading a partial scan as a shorter number.
- GS1-128 carries data with Application Identifiers: (01) for the GTIN, (17) for the use-by date, (10) for the batch, (00) for a pallet’s SSCC. Type them in brackets; check digits inside (01) and (00) are completed for you.
- Code 128 (ISO/IEC 15417) encodes letters, digits and symbols compactly; the writer switches between its character sets automatically for the shortest barcode. Code 39 (ISO/IEC 16388) is older and wider but still required by some defence, automotive and library systems. Avoid $ / + % before a letter in Code 39: scanners set to Full ASCII read a pair like /A as one character (!). Codabar survives in libraries and blood banks.
- Data Matrix, PDF417 and Aztec are 2D codes for serial numbers on parts, ID cards and tickets. For links and contact cards, a QR code is the better choice: make one with the QR code generator.
Size, quiet zones and colours
The module width (X) is the width of the narrowest bar. The GS1 General Specifications set EAN-13 and UPC-A at 0.33 mm (100%) and allow 0.264 to 0.66 mm at checkouts, with a minimum bar height that grows with X: 22.85 mm at the standard size. Shorter bars only read when the scanner’s line crosses them straight. ITF-14 and GS1-128 on cartons need X of at least 0.495 mm and bars 31.75 mm tall, because warehouse scanners read them from a distance.
The quiet zones are the empty margins on each side: 11X on the left and 7X on the right of an EAN-13, 9X on both sides of a UPC-A, 10X for Code 128 and ITF-14. Keep text and graphics out of them. For colours, scanners light the barcode with red light, so red, orange and yellow bars look white to them; the colour check estimates the contrast a scanner would see. Black or dark blue bars on white are safest. Turn the barcode 90° when it has to run down the side of a pack.
Printing tips
Print PDFs and label sheets at 100%. For thermal label printers, pick 203 or 300 dpi for PNG files so every module is a whole number of printer dots; the note under the resolution shows the module width you really get. Test the first print with a phone or a handheld scanner, or check it with the barcode and QR code scanner, which reads EAN, UPC and Code 128 from a photo too.