How to Create Product Barcodes — UPC, EAN & Code 128 the Free, Bulk Way

A Barcode Is the Difference Between “Listed” and “Sellable”

The moment a product moves through a real retail system — a store register, a warehouse scanner, a marketplace fulfilment centre, an inventory app on your phone — it needs a barcode that scans reliably. Without one, the item can't be checked out, tracked, or received. It's listed, but it isn't sellable.

Sellers hit two separate problems here, and most guides only answer one of them. The first is which barcode you actually need: a UPC, an EAN, a Code 128, something else? The second is purely practical — how do you turn that number into a clean, scannable, print-ready image, whether it's for one product or a catalogue of five hundred?

This guide answers both. We'll settle the symbology question, explain where the number is supposed to come from (the part almost every tutorial skips), then show the fast way to generate barcodes one at a time or in bulk from a spreadsheet.

UPC, EAN, or Code 128? Pick the Right Symbology First

“Barcode” isn't one thing — it's a family of formats called symbologies, and the right one depends entirely on where the code will be scanned. Pick wrong and it either won't scan or won't be accepted by the marketplace.

Here are the ones that actually matter for product sellers:

• UPC-A (12 digits) — the retail standard for products sold in the US and Canada; what you see on North American shelves
• EAN-13 (13 digits) — the global retail default used everywhere outside North America (Europe, the Middle East, Daraz, most of Asia)
• EAN-8 (8 digits) — a compact version for tiny packaging where a full EAN-13 physically won't fit
• Code 128 — the workhorse for internal SKUs, shipping labels, and warehouse/inventory systems; encodes letters and numbers and stays compact
• Code 39 — an older format for asset tags and industrial labels; letters and numbers, widely supported by cheap scanners
• ITF-14 — used on the outer shipping cartons and cases that hold multiple retail units

Where the Number Comes From (The Part Most Guides Skip)

This is the distinction that trips up new sellers, so it's worth being precise: a barcode generator turns a number into a scannable image. It does not, by itself, register a globally unique product identity. Those are two different things.

For retail marketplaces — Amazon, and many Daraz and Shopify categories — you need a GTIN: a UPC or EAN number issued by GS1, the global authority that guarantees every number is unique worldwide. You buy those from GS1 (or a legitimate reseller), and then you generate the barcode image from the number you were assigned.

For everything internal — your own warehouse, point-of-sale, price tags, or an inventory app — there's no registration at all. You make up your own SKU numbers and encode them as Code 128 or Code 39. This is where a free generator does the entire job end to end.

How to Generate a Barcode in 3 Steps

Once you know your symbology and your number, making the barcode itself takes seconds. You can do it free with BatchSet's Barcode Generator — no signup needed to try it.

1. 1Open the Barcode Generator and choose your symbology (UPC-A, EAN-13, Code 128, and more)
2. 2Type in the number or SKU — for UPC and EAN the tool validates the length and adds the check digit automatically
3. 3Download a crisp, print-ready PNG — or generate a whole batch at once (next section)

Generate Hundreds of Barcodes at Once from Excel

Making one barcode at a time is fine for a handful of products. For a full catalogue — or a fresh batch of inventory SKUs — you want to generate them all in a single pass instead of retyping numbers one by one.

BatchSet supports bulk generation straight from a spreadsheet, which is the fastest route when you already keep your products in Excel or a CSV:

1. 1Put every SKU or GTIN in a single column of an Excel or CSV file
2. 2Upload the sheet to the Barcode Generator (this uses the same Excel Batch flow as the bulk image tools)
3. 3Choose one symbology and size for the whole batch — Code 128 for internal SKUs, EAN-13/UPC-A for retail numbers
4. 4Download every barcode as a single ZIP, each file named after its code so labels are easy to match up

Make Barcodes Actually Scan: Size, Quiet Zone & Print Quality

A barcode that looks perfect on screen can still fail at the register if it's printed too small, saved in a lossy format, or cropped too tight. A few rules keep every code reliably scannable:

• Keep the quiet zone — the blank margin on both ends of the bars is part of the barcode; scanners need it, so never crop right up to the first and last bar
• Respect the size — a UPC-A/EAN-13 has a nominal print size of roughly 37×26mm at 100%; shrinking below about 80% starts to cause scan failures
• Export PNG, not JPG — PNG keeps the bars razor-sharp; JPG compression blurs the edges between bars and is a common reason cheap scanners misread
• Print at 300 DPI on white — pure black bars on a plain white background, no colour tints or textured stock behind them
• Test one before printing a thousand — generate a single label, print it, and scan it with your phone's camera or a handheld scanner first

Common Barcode Mistakes

Most barcode problems trace back to the same handful of errors — all easy to avoid once you know them:

• Using a made-up number as an official UPC/EAN on a marketplace instead of a GS1-issued GTIN
• Choosing the wrong symbology — e.g. Code 39 where the retailer expects a scannable EAN-13
• Cropping off the quiet zone so the scanner can't find the start/end of the code
• Saving a blurry JPG instead of a clean PNG, which softens the bars
• Printing too small or at low DPI, so the bars merge together
• Trying to hand-calculate the check digit — let the generator add it and avoid a typo