Barcode generator

Which barcode format fits which job

The formats, what each holds and the clear space it needs

Format	Holds	Usual job	Clear space
UPC-A	12 digits	Products in US and Canadian stores	9 modules each side
UPC-E	8 digits	Small packs in those stores	9 left, 7 right
EAN-13	13 digits	Products elsewhere, and books	11 left, 7 right
EAN-8	8 digits	Very small packs	7 each side
Code 128	Any ASCII text	Stock, bins, shipping labels	10 each side
Code 39	43 characters	Older label systems that name it	10 each side
ITF-14	14 digits	Shipping cartons	10 each side
Data Matrix	Up to 1,556 bytes	Tiny parts, medical items	1 all round
PDF417	About 1,100 bytes	Long records on a label	2 all round
QR Code	Up to 2,331 bytes at the error correction level set here	Links for phones	4 all round

The format list runs this test on your own text as you type. A format with a dashed outline cannot hold what you typed, and it says what it needs. Click it anyway to see the full reason.

Barcode sizes in real units

A printer cares about the width of the narrowest bar, so that is the size control here, and everything else follows from it. The size readout gives the full width and height in millimeters or inches, with clear space included.

For the retail formats, GS1 sets the range: a 0.264 mm to 0.66 mm narrow bar. Cartons have their own range, from 0.495 mm to 1.016 mm. Code 128 and Code 39 have no GS1 size outside the supply chain, and 0.33 mm is a good place to start.

What the three file types are for

The PDF draws black bars in device gray and any color you pick in RGB, never CMYK. A print shop that works in CMYK converts the file, and black stays black.

SVG, PNG and PDF: which file suits which job

File	Best for	Why
SVG	Designers, web, cutting machines	Pure vector, with digits drawn as shapes so no font can go missing
PDF	Print shops, page layouts	Vector, with the page cut to the exact barcode size
PNG	Label printers, Word, spreadsheets	Whole printer dots, with the resolution stored so it places at true size

Colors that scan and colors that do not

A typical scanner reads under red light, around 660 nm, which is the light GS1 specifies for grading. Under red light, red bars look the same as white paper and vanish, and a pale blue background turns dark. Black on white is safest, and dark blue or dark green bars work on a white or pale yellow background. Light bars on a dark background fail on most retail scanners. The tool warns you about colors that look risky under red light, though that is only a rough check. A real test on your printer settles it.

Tools for one code and for a whole list

Each format also has a tool built around its own job. The UPC generator reads the opening digits of your number, and the ITF-14 tool builds a carton number from your item number. The SKU generator turns product options into a full list. To test a number you were given, try the check digit calculator.

Before the first print

How barcodes work follows a read from the red light to the number that reaches the till. Making a barcode from the number up compares every route, this one included, and says which number each job needs. Designers can place a barcode from here into a Canva layout without losing sharpness. A phone is enough to check a printed sample before a run. The story of the first checkout scan is in who invented the barcode.