Guides

Updated August 2026

Free checkers that run the same validators as the catalog audit, one value at a time:

• GTIN check digit checker — validate a GTIN-8, UPC-A, EAN-13, or GTIN-14.
• GS1 Digital Link syntax validator — check a Digital Link URI's primary key, qualifier order, and attributes.
• Artwork preflight — check a print file's codes before it goes to press.
• Sample readiness report — a worked example of what the free catalog audit returns.

Guides

• What Sunrise 2027 means for a brand
  What the industry target covers, what it does not require, and how a brand can prepare for retailer adoption.
• GS1 Digital Link and plain QR codes at checkout
  A retail POS can read the GTIN only when the QR URL uses GS1 Digital Link syntax. What separates the two, and what a plain QR code costs you at checkout.
• Print requirements for GS1 QR codes on retail packaging
  Module size, quiet zones, contrast, and placement determine whether a 2D code can be scanned at checkout.
• How the GTIN check digit works, and why yours may be wrong
  The mod-10 algorithm behind every UPC, EAN, and GTIN, with the spreadsheet errors that corrupt product identifiers.
• Dual marking: running UPC and a 2D code on the same package
  Why both codes coexist through the transition, where to place them, and how to avoid the double-scan problem at checkout.
• How Excel destroys your GTINs, and how to get them back
  Leading zeros, scientific notation, and the fifteen digit ceiling. Which damage is recoverable, which is not, and how to tell before a label is printed.
• What a GS1 resolver does
  How link types, linksets, and lot-specific routes differ from a basic URL redirect, and what a resolver has to return before a scan reaches the right page.
• Which brands need 2D barcodes first
  A category-by-category way to assess retailer, traceability, and regulatory pressure before changing packaging.
• GS1 Application Identifiers used in retail 2D codes
  The identifiers for GTIN, batch, expiry, serial, and product variant, including their required order in the URL.
• The EU Digital Product Passport, in plain terms
  How Digital Product Passport requirements are introduced by product category, and where GS1 Digital Link may fit.
• FSMA 204 and 2D barcodes: what the rule actually requires
  The FDA food traceability rule, its enforcement posture, and how lot-level 2D codes can help without being mandated.
• Choosing the domain that goes on your packaging
  How a brand-owned subdomain keeps a printed URL portable when providers or websites change, and why the domain on the pack is the hardest choice to reverse.
• What a 2D barcode migration can cost
  The cost categories and quote details to collect for artwork, printing, resolver software, and verification.
• A working checklist for Sunrise 2027
  Twelve steps in the order they should happen, with the reason each comes when it does, from catalog cleanup through resolver setup and a scanned sample.
• Common questions about GS1 Digital Link
  Straight answers on cost, mandates, phone compatibility, existing QR codes, and what happens if your resolver goes down.

More

• Documentation — how the audit, resolver, and product pages work.
• Partner referrals — for packaging designers, prepress shops, and label printers.