When you import products in bulk (e.g. Matrixify-format spreadsheets), a single wrong Variant ID or SKU pairing can rename an existing variant's SKU or duplicate a product — and you often don't notice until it's too late. SKU Pre-Validator checks your file **before** you upload it, comparing every row against the products that already exist in your store.

• Duplicate SKUs inside your file — the same SKU on multiple rows
• Empty SKUs — rows missing a SKU
• New vs. update — whether each SKU is new to your store or will update an exist