How to Generate Product Barcodes for Inventory

Internal codes versus retail codes

There are two different jobs here. If you sell through retailers, your products need official GS1 identifiers (the numbers behind EAN-13 and UPC-A), which you license from GS1. A generator turns those numbers into scannable images, but it does not assign the numbers.

If the barcodes are purely for your own warehouse or stockroom, you can invent your own scheme and encode it with Code 128. No registration required.

Designing an internal scheme

• •Keep codes short but unique, a prefix plus a sequential number works well.
• •Avoid encoding meaning that might change, like a shelf location.
• •Use Code 128 for internal labels; it is compact and supports letters and numbers.
• •Reserve EAN-13 or UPC-A for items that will be scanned at retail checkout.

Generating many at once

Typing codes one at a time does not scale. Export your item list to a CSV with a column of codes, then use a batch generator to turn every row into a labelled barcode and download them as a ZIP.

A browser-based batch tool keeps that product list on your machine instead of uploading it to a service.

Printing that scans

Print at the highest resolution your label printer supports and leave generous quiet zones on the left and right of the code. Thermal printers are the workhorses here because the contrast stays crisp.

Avoid scaling barcodes non-proportionally; stretching them in one direction breaks the bar-width ratios scanners rely on.

Test before you commit

Print a single label, scan it with the exact device your team will use, and confirm it reads on the first try. Only then run the full batch.