Paste your product CSV. It tells you which line will fail, before Shopify rejects the whole file and names no row.
What it checks. A hidden BOM on the first line, rows with the wrong number of fields, empty handles, prices that are not numbers, duplicated handles, and SKUs whose leading zeros look lost.
Everything runs in your browser. Nothing is uploaded, and no file leaves the page. By IIX Lab - more free tools.