Is this guide for you? If you manufacture, formulate, or otherwise own-brand what you sell and don't yet have a real GTIN, you need both steps below. If you resell other brands' already-barcoded products, you almost certainly already have valid GTINs from those brands. Skip to Step 2 and print what you have. Assigning your own numbers to someone else's product creates the exact mismatch problem this guide is trying to help you avoid; our guide to setting up a GS1 Company Prefix covers that distinction in more depth.
Why "Print a Barcode" Actually Means Two Different Things
Search for how to get a barcode onto a Shopify product and you'll find plenty of results, but they tend to split cleanly into two piles that never talk to each other. Shopify's own help docs and a handful of app-listing blogs will show you where to type a number into the barcode field. A separate set of app listings will show you how to lay that number out on a sheet and print it. Almost nothing walks the whole distance: get a number that's really yours, then put it on a label.
That gap matters because the two jobs fail differently. Getting the number wrong doesn't show up immediately. The barcode still scans, the label still prints, and the product still ships. It surfaces weeks later, when Amazon or Walmart Marketplace cross-references the number against GS1's own registry and rejects the listing. Printing the label wrong is obvious the moment you look at the sheet. One problem hides; the other doesn't. Solving them together, in order, is the point of this guide.
| GS1 Assistant (Step 1) | Label Wizard (Step 2) | |
|---|---|---|
| Job | Assigns a real GTIN from your own GS1 prefix | Prints that GTIN onto a label |
| Free | First 20 GTINs | First 20 label generations a month |
| Price | $4.99/month (500 GTINs) | $14.99/month (unlimited) |
| Formats | GTIN-14, UPC, EAN-13 | EAN-13, UPC, GTIN-14, GS1-128, Code 128 |
Is Shopify's Own Barcode Field a Real GTIN?
Shopify's barcode field is a plain text box. Type in twelve digits, thirteen digits, or your cat's birthday, and Shopify saves it without checking whether it's a real, GS1-licensed GTIN. That's true whether you typed the number by hand or an app filled it in for you. A lot of "barcode generator" apps, and Shopify's own internal Retail Barcode Labels feature, mint a number from a pattern or from a variant's own ID rather than obtaining one from GS1. A number built that way can look completely correct: right length, valid check digit, scans fine at the register. What it isn't is licensed to your company, which is what Amazon and Walmart check against.
What goes wrong splits into two different problems, and neither is what a licensed GTIN is supposed to produce:
A barcode that collides with a different company's product. A merchant reviewing a rival barcode-generator app wrote: "It shows invalid GTIN. When we scan barcodes it shows different products from other merchants. Not legitimate." (Yanet, 1★).
A milder, more common failure: a generated number colliding with the merchant's own other products. One review (Shopify free app, 2★) describes a scheme that "uses the last 8 numbers from the variant URL… occasionally it creates duplicates," and another (an EasyScan merchant) reported "the arbitrary ending 8 digits… caused issues with duplicate barcodes across variants."
Both are real, and they're different problems.
Left Foot Software sells the legitimate alternative to both failure modes: GS1 Assistant assigns GTINs from a GS1 Company Prefix your business owns, and Label Wizard prints them. The argument holds up on its own merits: a number minted from a variant ID was never allocated to you by GS1, so it carries no guarantee of uniqueness outside your own store. That's a licensing fact, not a review finding. Still, you should know who's telling you this before you weigh it.
Either way, the fix is the same: assign a GTIN from a GS1 Company Prefix you own, which is Step 1 below.
Step 1: Assign a Real GS1 GTIN
What GS1 Assistant Does
GS1 Assistant assigns GTINs to your products and variants from a GS1 Company Prefix your business already licenses, checking format and check digit as it goes and flagging duplicates before they ship to Amazon or Walmart. If you don't have a prefix yet, licensing one is a separate step through GS1 directly, not through Shopify or any app. In short:
- Add your prefix once, in GS1 Assistant's setup screen.
- Assign GTINs to products and variants from that prefix. The app checks format and check digit as you go.
- Run duplicate detection across your catalog, since a bulk import is the most common place two variants end up sharing a GTIN.
Our full walkthrough on getting and connecting a GS1 Company Prefix covers each of those steps in more depth than this guide needs to.
Don't have a real GTIN yet? Assign your first 20 free
GS1 Assistant handles the assigning, checking, and duplicate detection. The prefix itself still comes from GS1; the app takes over from the moment you have one.
Why a Real GTIN Matters Downstream
The payoff shows up the moment Amazon or Walmart checks your listing rather than just scanning it.
"products appear in Verified by GS1 shortly after uploading... no worry about Amazon or Google Shopping — they work"
Jessica Rich · GS1 Assistant merchant
That's the difference a licensed number makes over one that merely looks right: nothing to fix later, because there was nothing wrong with it to begin with.
GS1 Assistant's free plan covers your first 20 GTINs. Paid plans start at $4.99 a month for up to 500 GTINs, or $11.99 a month for unlimited, both billed every 30 days.
Step 2: Print Your GS1 Barcode Labels
What Label Wizard Does
Once a product has a real GTIN, Label Wizard prints it:
- Standard GS1 formats. EAN-13, UPC, GTIN-14, GS1-128, and Code 128, plus QR codes, with automatic format detection.
- 418 templates, for Avery, Online Labels, or Uline, or build a custom size from rows, columns, and margins.
- Every variant gets its own label. Long names wrap instead of getting cut off, and you can preview on real products before spending a credit.
Put simply: "Renders the barcode you already own — never invents one." That doesn't mean it's slow to set up, though:
"Just installed Label Wizard and was able to design and print professional looking labels almost immediately!"
GC Shoes · Label Wizard merchant
If a Product Doesn't Have a Barcode Yet
You don't have to finish Step 1 before you can use Label Wizard at all. A product missing a barcode still prints a clean label with the barcode element simply hidden, so name, price, and SKU labels work while you're still mid-setup on the GTIN side.
Already have real GTINs? Print your first labels free
Label Wizard's Pay As You Go plan covers your first 20 label generations at no charge, then scales with usage. Need GTINs first? GS1 Assistant's free plan covers your first 20.
Label Wizard's Pay As You Go plan is free to install, with your first 20 label generations free each month; usage above that is billed per label generation on a sliding tier. A Pro plan at $14.99 a month, or $150 a year, adds unlimited templates and unlimited label printing.
Common Mistakes When Going From GTIN to Label
1. Assuming Shopify's Barcode Field Validates Anything
A merchant types a 13-digit number into the barcode field, sees it save with no error, and assumes that means it's correct. Shopify has no way to check it against GS1's registry at save time. The number that "worked" when it saved is often the same one that gets flagged three weeks later, once Amazon or Walmart actually cross-references it.
2. Trusting a "Barcode Generator" App to Assign Real GTINs
A number that scans and passes a format check isn't necessarily one GS1 has licensed to you. If an app's "barcode generator" feature didn't ask you for a GS1 Company Prefix at any point, it isn't assigning real GTINs, whatever it calls the numbers it produces.
3. Expecting Label Wizard to Assign or Create a Barcode
Label Wizard's job is printing the barcode a product already has, not deciding what that barcode should be. If a product doesn't have a real GTIN yet, GS1 Assistant is the app that assigns one; Label Wizard picks up from there.
4. Printing Before Confirming Verified by GS1 Status
A GTIN can look assigned correctly and still fail behind the scenes. A formatting slip in one digit is more common than a wrong prefix. Our prefix-setup guide's section on confirming your setup is working is worth five minutes before you print a whole sheet of labels for a product line, rather than finding out from a rejection notice after the fact.
Frequently Asked Questions
Can Label Wizard generate or create barcodes for me?
Label Wizard prints barcodes you already own — it doesn't create them. If you need real, licensed GTINs, that's GS1 Assistant, our separate app. It assigns numbers from your own GS1 company prefix rather than inventing one, so they're genuinely yours and won't clash with another company's products. It's free for your first 20.
You can still use Label Wizard meanwhile — a product with no barcode prints a clean label with the barcode element simply hidden, so name, price and SKU labels all work.
Do I need both apps, or just one?
Depends on where your product data stands today. If you own-brand what you sell and don't have a real GTIN yet, you need both: GS1 Assistant to assign the number, Label Wizard to print it. If you resell products that already carry valid GTINs from the brand that made them, you only need Label Wizard. There's nothing to assign, only something to print.
Which barcode formats does Label Wizard support?
Label Wizard supports standard GS1 barcodes: EAN-13, UPC, GTIN-14, GS1-128, and Code 128, plus QR codes, with automatic format detection so you don't have to specify which one you're printing.
What if my product doesn't have a barcode yet?
Label Wizard prints the barcodes your products already have. To get GTINs in the first place, see GS1 Assistant.
Is this different from Shopify's built-in barcode field?
Yes. Shopify's barcode field is a text box that saves whatever you type without checking it against GS1's registry. A number that passes that save isn't the same as one GS1 has actually licensed to your company. That gap is exactly what causes rejections on channels that verify identifiers, weeks or months after a product goes live, covered above.
How much does each app cost?
GS1 Assistant's free plan covers your first 20 GTINs; paid plans start at $4.99 a month for up to 500, or $11.99 a month for unlimited. Label Wizard is free to install, with your first 20 label generations free each month before usage charges apply, or $14.99 a month (or $150 a year) for unlimited templates and unlimited printing.
One Workflow, Not Two Apps to Compare
Assigning a real GTIN and printing it are two different jobs, and most of what's written about Shopify barcodes only covers one or the other. Getting a number that's actually licensed to you is what keeps a listing from getting flagged weeks after it ships; getting it onto a label is what makes the product sellable in the first place. Treat them as one workflow rather than two separate problems to research, and the order stops mattering. Assign first if you're starting from scratch, or jump straight to printing if the GTIN side is already handled.
If you're setting up GTINs from scratch, our guide to GS1 Company Prefixes covers that in more depth. If you're comparing label-printing apps more broadly, our roundup of Shopify label-printing apps covers that ground too. No other app in this category appears to make both halves of this workflow, which is the gap this guide (and these two apps, together) is built to close.