Choose the right barcode type
Code 128 handles letters and numbers for stock labels and internal IDs. EAN and UPC are for retail product numbers. Use the type required by the system that will scan the label. For a website address or Wi-Fi details, make a QR code.
The white space at each end is the quiet zone. Keep it clear when placing the image in a document. An SVG stays sharp when resized; a PNG has a fixed pixel size.
A worked example
For EAN-13, 590123412345 becomes 5901234123457. The final digit is calculated from the preceding digits; a full number with the wrong check digit is rejected.
Before you use the result
Generating an image does not register a product number. Use your assigned retail number for a real product. Print size, contrast, packaging and the scanner affect readability. Batch labels, GS1 data fields and PDF sheets are not included.