Repair the CSV structure first
A comma inside a field must be enclosed by CSV quotes. For example, a title cell containing Cotton, washed is written as "Cotton, washed". A quote inside a quoted field is doubled. Spreadsheet export usually handles this more reliably than manually editing raw CSV.
If a record has more or fewer fields than the header, resolve that before investigating its prices or variants. A multiline quoted description occupies several text lines but remains one CSV record. The checker reports the starting line.
Use recognizable Shopify columns
The free checker is for files already in Shopify format. It recognizes common current and legacy field names, including SKU and Variant SKU. Including both forms of the same field creates ambiguity and is flagged.
A supplier sheet with columns such as Item code and Retail price needs mapping first. Use supplier preparation for that transformation. Changing a header alone does not resolve product grouping, missing facts or an unsuitable price.
Keep SKUs separate from product grouping
A SKU identifies a sellable item; a handle groups rows into a product. Reusing a SKU receives a warning because that may be intentional. Repeating the same size/color combination within one product is a separate error in the checker.
Review the first product row and its later variant rows together. Keep option names consistent and confirm that repeated rows belong to the same product. Do not delete a variant just to silence a warning without checking the source.
Know what free cleanup changes
The free cleanup download normalizes recognized headers, CSV quoting and empty rows while preserving product values. It refuses unsafe or ambiguous inputs instead of inventing fixes. It cannot choose a correct selling price, manufacture a missing SKU or decide which conflicting variant is real.
Use the downloadable findings report for the decisions that need your attention, then check the revised file again. Up to 5 MiB, 20,000 data rows and 250 columns are supported in the browser checker.
Review the import context too
The checker never connects to your store or fetches image URLs. It cannot detect an existing product collision, verify a supplier’s claims or guarantee that Shopify will accept a file. Back up existing data and inspect Shopify’s import preview.
The browser checker requires no sign-in or upload. File contents stay in browser memory; optional usage counts exclude file contents, filenames and product values.
| Finding | Meaning in ListMint | Next step |
|---|---|---|
| Wrong column count | A record does not match the header width. | Look for unquoted commas or a broken quoted cell. |
| Duplicate option combination | Two variants in one product share the same options. | Confirm whether they are duplicates or different products. |
| Duplicate SKU | Warning: an identifier is reused. | Check the intended inventory and fulfillment identity. |
| Price includes $ or separators | The numeric format needs review. | Confirm the amount and export a plain decimal value. |
| Named bedding size, no dimensions | Optional review warning. | Use confirmed measurements; do not guess from “King”. |
| Valid image URL | Only URL syntax was checked. | Verify the actual public image yourself. |
Try it with the sample.
Download the fictional supplier CSV, then use the free preparation preview. For a file already in Shopify format, use the free CSV checker.
Check my Shopify CSV free ↗Reference and limits
These instructions describe ListMint’s supported behavior. Shopify’s accepted fields and import options can change. Check Shopify’s official product CSV documentation and your store’s import preview. ListMint does not guarantee import success.
Customer source files are never published in these examples. Read how file processing and optional measurement work.