How to clean, combine and match CSV files
Load and inspect
Use a UTF-8 CSV or TSV up to 5 MB, 10,000 rows and 100 columns. Select comma, semicolon or tab delimiter before loading. Profile columns for empty, distinct and repeated values. Source files remain on your device.
Build an ordered recipe
Add up to 30 per-column rules for trimming, whitespace, case, literal replacement, filling empty values, prefixes or suffixes. Number rules require explicit decimal and thousands separators. Date conversion requires an explicit day/month/year order; ambiguous dates are never guessed.
Preview before applying
Review proposed changes, error count and rows removed. The preview shows at most 100 change examples or errors and the first 20 result rows. Any conversion error blocks Apply. A successful Apply changes the working copy only. One-step undo restores the previous working copy.
Remove duplicates deliberately
Choose one exact key column or all columns, and retain the first or last row. Deduplication runs after your cleaning rules. Empty key values count as duplicates too. This is row removal, not a merge of conflicting field values.
Combine files safely
Append aligns exact header names and fills missing fields with empty strings. Matching uses exact case-sensitive keys against a lookup whose nonempty keys must be unique. A left join keeps unmatched rows; an inner join removes them. Conflicting lookup names receive lookup_ prefixes. Output remains within the same bounded working limits.
Export for your destination
Generic CSV adds apostrophes to formula-like values for spreadsheet safety. JSON preserves exact strings. Use the product workspace to map simple products to Shopify draft or WooCommerce draft-and-hidden exports. Multi-variant products are outside these platform adapters. Test a small import first with existing-product updates disabled.
Reuse rules with care
Recipe JSON includes column names and literal replacement values but no source rows. These values can still be sensitive. Save recipes explicitly on your device, back them up privately, and preview each imported recipe against its new source file.
WooCommerce export follows the official product CSV schema: simple products, Published false, visibility hidden. Store import readback remains an owner acceptance check.