GTIN and barcode shape
Find rows where GTIN or Variant Barcode values look blank, malformed, or inconsistent across product variants before the feed app sends them downstream.
Merchant Center CSV preflight
Check Shopify CSV identifiers before Merchant Center sync.
Use this when products or variants do not sync cleanly to Google Merchant Center because GTIN, MPN, barcode, Custom Product, or condition fields are inconsistent across Shopify CSV rows.
Copy a short identifier checklist before retrying a Merchant Center feed sync.
MPN values
Review MPN fields that look like product URLs, placeholder text, or mixed manufacturer part number formats across related variants.
Custom Product flags
Check whether rows without GTIN, barcode, or MPN need Custom Product set deliberately instead of leaving identifiers half-filled.
When to use this page
Use it for Shopify Community or agency conversations about MPN values not syncing, Google Merchant Center identifier warnings, variant barcode confusion, and feed cleanup before Performance Max or Shopping campaigns.
What the export gives you
The useful files are the Issues CSV, field mapping export, review rows, and blocked rows. They help you separate identifier cleanup from broader feed-app setup.
Privacy and limits
The checker runs locally in the browser. It does not connect to Shopify, Google, Merchant Center, feed apps, or a server, and it does not guarantee Merchant Center approval.
Need a cleanup pass after the report?
Run the free checker first. If the Issues CSV shows identifier problems across many variant rows, copy a short request and share only a redacted report or sample.
Copy a cleanup request after you have an Issues CSV or report.