Barcode Generator

Q: Which barcode type should I use?

Code 128 unless something forces your hand. It handles all printable ASCII, packs pairs of digits into single symbols so numeric codes come out about half as wide, and is what modern warehouse and logistics systems expect. Use EAN-13 or UPC-A only for products sold at retail, since those numbers must come from GS1. Use ITF-14 for shipping cartons, and Code 39 only when a specific older scanner or system requires it.

Q: How small can I print a barcode?

It depends on the symbology and is governed by the X-dimension — the width of the narrowest bar. EAN and UPC have a nominal X of 0.33mm and a floor around 0.264mm, which is 80% magnification. Code 128 and Code 39 are commonly printed at 0.25mm and should not go below about 0.19mm. The analysis panel checks your setting against the minimum for the type you picked and warns you before you print, because this is the failure that only shows up after the labels are made.

Q: Can I make up my own EAN-13 or UPC number?

For internal use, yes — prefixes 20 through 29 are reserved for in-store numbering and this tool flags when you are using one. For anything sold through another retailer, no: those numbers must be allocated by GS1, and an invented one will either duplicate a real product or be rejected outright. This tool will happily encode any valid-format number, so the responsibility for the number itself is yours.

Q: What is a check digit and do I need to include it?

It is a digit computed from all the others, which the scanner recalculates on every read and compares — if they disagree, it rejects the scan rather than reporting a wrong number. For EAN, UPC and ITF you can either type the full number including the check digit, in which case this tool verifies it and tells you if it is wrong, or leave it off and have it calculated. Code 128 has a check symbol built in that is never printed as text. Code 39's check character is optional and off by default.

Q: Why does my printed barcode not scan?

In rough order of frequency: the quiet zone was cropped, the symbol was scaled down below the minimum bar width, it was printed on a coloured or reflective background, or the printer resolution smeared the bar edges. Thermal printers in particular spread ink slightly, which narrows the white gaps — printing at a slightly larger X-dimension usually fixes it. Export as SVG if your label software supports it, since that keeps exact millimetre dimensions rather than resampling a raster image.

Q: Should I export PNG or SVG?

SVG if your label software or printer driver accepts it. The file carries exact millimetre dimensions and vector bars, so nothing is resampled and the bar edges stay perfectly sharp at any size. Choose PNG when you need a raster image, and match the export dpi to your printer — 203 dpi for most thermal label printers, 300 for office and commercial print.

Generate Code 128, EAN-13, UPC-A, EAN-8, Code 39 and ITF-14 barcodes, sized for real printing.

Barcode type

Value to encode

Printed size

X-dimension 0.250 mm per narrow bar

Bar height 15 mm

Export resolution

Format

Print the number below the bars

What It Does

This tool encodes a value as a linear barcode in whichever symbology you need, and then does the part most generators skip: it works out whether the barcode will actually scan at the size you are about to print it. Bar width is measured in fractions of a millimetre, and a symbol printed 20% too small reads perfectly on screen and fails on the shelf. The analysis panel gives you the printed width, the magnification against the standard, and the quiet zone you must leave blank.

When to Use It

You are printing asset or inventory labels and need Code 128, which packs digits two to a symbol and stays compact.
You are putting a product on a shop shelf and need a valid EAN-13 or UPC-A with a correct check digit.
You are labelling shipping cartons and need ITF-14 at the fixed size the standard requires.
You are working with older warehouse or laboratory equipment that only reads Code 39.

Worked Examples

5901234123457

A complete EAN-13 with its check digit. The analysis confirms the digit is correct and reports the symbol as 95 modules — every EAN-13 is exactly 95 modules regardless of the number.

SHIP-2026-0042

Mixed letters and digits in Code 128. Compare its width against the same value in Code 39 to see why Code 128 is the default for anything that has to fit a small label.

10012345678902

A shipping carton code. ITF-14 encodes digits in interleaved pairs, so the length must be even — the analysis also reminds you to add the bearer bar your label template needs.

Common Mistakes

Cropping the quiet zone. The blank margin either side of the bars is part of the symbol, not padding — a scanner uses it to find where the code starts. Designers routinely trim it to fit a layout, and it is the most common cause of a barcode that looks perfect and will not read.
Shrinking the barcode to fit the space. Bar width has a physical minimum, and scaling a symbol down past it produces bars too narrow for the scanner to resolve, especially on a thermal printer where ink spread closes the gaps further. The analysis panel flags this against the minimum for your chosen symbology.
Inventing an EAN-13 or UPC-A number. Retail barcode numbers are allocated by GS1, and a made-up one will either collide with a real product or be rejected by the retailer. Use the 20-29 in-store prefixes for your own internal labelling, and buy a real prefix for anything sold elsewhere.
Using Code 39 out of habit. It is roughly three times wider per character than Code 128 and has no lowercase. Unless a specific piece of equipment demands it, Code 128 encodes the same data in a fraction of the space.
Printing on a coloured or dark background. Laser scanners read the contrast between bars and spaces, and a dark background destroys it — which is why the preview here is always drawn on white regardless of the page theme.

Features

Code 128 with automatic A/B/C mode switching

EAN-13

EAN-8

UPC-A

Code 39 and ITF-14

Automatic check digit calculation and verification

Printed width and magnification against the standard

Quiet zone size in millimetres

Scanner tolerance warnings before you print

PNG export at 203

300 or 600 dpi

SVG export at exact millimetre dimensions

Runs entirely in your browser

How to Use

1. Choose the barcode type — Code 128 if you have a free choice, EAN-13 or UPC-A for retail products. 2. Enter the value; for EAN, UPC and ITF you can leave off the check digit and it will be calculated. 3. Set the X-dimension and bar height, watching the magnification figure in the analysis. 4. Export as SVG if your label software accepts vector, or PNG at your printer's dpi. 5. Print a test label and scan it with the actual scanner before running the batch.

Frequently Asked Questions

Which barcode type should I use?

How small can I print a barcode?

Can I make up my own EAN-13 or UPC number?

What is a check digit and do I need to include it?

Why does my printed barcode not scan?

Should I export PNG or SVG?

Embed this Barcode Generator

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Everything runs in your browser — nothing you type is uploaded or stored. This tool generates barcode symbols from numbers you supply; it does not allocate or register them. Retail barcode numbers (EAN-13, UPC-A, ITF-14) must be obtained from GS1 to be globally unique, and numbers you invent may collide with existing products. Always test a printed label with the scanner that will read it before committing to a production run.