How to add a GS1 Digital Link QR code next to your UPC
You don't convert a UPC into a QR code. The UPC stays on the pack, and you add a 2D code that carries the same GTIN. GS1 US's advice for brands is exactly that: "Add 2D barcodes to existing packaging; ensure any existing QR codes are updated with GS1 Digital Link standards and include your Global Trade Item Number (GTIN)."
The steps
1. Find your GTIN
The number under your barcode is the GTIN. A UPC-A is a 12-digit GTIN, an EAN-13 is 13 digits, and the full form is 14. You keep the GTIN you already have; no new numbers are needed.
2. Pad it to 14 digits and check it
Add leading zeros until it is 14 digits long (a 12-digit UPC-A gets two zeros in front). The last digit is a check digit calculated from the others, and padding doesn't change it. Run it through the free check-digit validator before anything is printed, because a typo that is the right length will still look fine on a label.
3. Build the address the QR will contain
A GS1 Digital Link address is the resolver's host, then /01/, then the 14-digit GTIN:
https://qr-42.com/01/00000012345007
Add /10/ and a batch/lot number if the code should be specific to a lot. A QR code that holds only a plain website address won't do: GS1's guidance is that the code follow GS1 Digital Link and include the GTIN, which is what lets a store's scanner read the GTIN out of it. How the resolver reads the address.
4. Claim the GTIN and choose where it goes
In QR Code 42 you sign in, claim the GTIN, and publish a link: your product page, a page per language or country, or a different page for a specific lot. You can change the destination later without touching the label.
5. Export the dual label
The label export gives you the QR and your UPC-A or EAN-13 together, each sized to GS1's minimums, as SVG or PNG artwork for your packaging designer.
6. Test before you print
- Scan the proof with a phone and confirm it lands where you expect, in the languages you published.
- Scan the UPC with a normal barcode scanner and confirm it still reads.
- Ask your retail buyers whether they want to see a dual-marked pack first. What to ask the stores.
7. Print, and keep the UPC
A store with an older 1D-only scanner reads the UPC as it always has. A store with a 2D scanner can read the QR, and a shopper's phone can read the QR either way.
Common mistakes
- Replacing the UPC. Don't, during the transition. Stores' scanners upgrade on their own schedules.
- Encoding a plain website address. A scanner can't get a GTIN from it. Use the GS1 Digital Link format.
- Skipping the check digit. A wrong digit means the code won't resolve for anyone.
- Printing too small or without a quiet zone. Use the sizes in the exported label.
- Not testing the proof. A printed label can't be recalled.
Why not just a normal QR generator?
A generic QR generator makes a code for a web address. A GS1 Digital Link code is a different thing: it carries your GTIN in the format GS1 specifies, so a store's 2D scanner can use it at checkout and a phone can use it too, and it points at a resolver so the destination can change. That is the job QR Code 42 does.
Source for the packaging guidance: GS1 US, Sunrise 2027. This page summarizes publicly available GS1 guidance; it isn't official GS1 material and isn't legal or compliance advice. QR Code 42 is an independent service and is not affiliated with or endorsed by GS1.