Free barcode generator

Which barcode type should you use?

Most people should pick Code 128. It encodes any ASCII text (letters, digits, symbols) in a compact code, which is why it runs shipping labels, asset tags, warehouse bins, and internal inventory. Code 39 is older and less dense. It holds uppercase letters, digits, and a few symbols (- . space $ / + %) and takes more width for the same data, so use it when a legacy scanner or system already expects it. EAN-13 and UPC-A are the retail barcodes you see on packaged goods. EAN-13 is the global standard (13 digits) and UPC-A is the North American version (12 digits). Reach for those two only when you are putting a product on a shelf and you already have a real product number to encode.

This does not give you a valid retail UPC

Here is the part most barcode sites skip. This tool encodes whatever number you type. It does not assign you a number that retailers and their systems will accept. A barcode that scans and looks up correctly in a store has to trace back to a GS1 company prefix, the registration that makes your product number unique worldwide. You buy that from GS1 (gs1.org), then build your EAN-13 or UPC-A from the prefix they issue. So generate here to design packaging, test your printer, or mock up a label. Buy a real GS1 number before you list a product in a store or on a marketplace that checks it.

Check digits, in plain terms

The last digit of an EAN-13 or UPC-A is a check digit, a number calculated from the others so a scanner can catch a misread. You do not have to work it out. Type the 12 base digits for an EAN-13 (or 11 for a UPC-A) and the tool appends the correct final digit. Type the full 13 (or 12) and it validates the digit you entered and flags it if the math does not match. Code 128 and Code 39 do not show a check digit to you; Code 128 uses one internally and the encoder handles it.

Printing a barcode that actually scans

A barcode is only useful if a scanner reads it on the first pass. Four things matter. Keep the quiet zone, the empty white margin on the left and right of the bars, at least a few millimeters, or the reader cannot tell where the code starts. Keep the contrast high: dark bars on a light background, ideally black on white, never on a dark or busy color. Do not shrink it too far. A retail EAN or UPC is about 3cm wide at full size, and going much smaller is the top reason a code will not read; internal labels need enough width for the scanner you use. Download the SVG for anything you plan to resize, because it stays sharp at any size while a stretched PNG goes fuzzy. Then test-scan the printed copy with a real scanner or a phone app before you run the whole batch.