HOW IT WORKS
Learn how to compare CSV files by a single ID or joint key, review changes, and export reports.
Select or drag an old CSV and a new CSV onto the tool. Files must use UTF-8 or UTF-8 BOM and comma separators. Quoted commas, quoted newlines, Chinese text, and empty fields are supported. File information comes from the actual parser.
Pick a unique ID, SKU, email, or multiple fields together. Recommendations check uniqueness in both files. A joint key must be complete and unique. Duplicate or blank keys stop comparison with record-level diagnostics; records are never paired by row number.
Review added, removed, modified, and unchanged records. Modified rows contain old and new values and can be expanded to show every original field. Search, filter by changed field, sort by key, and download one of five CSV reports.
String comparison is strict by default: leading zeros, spaces, and case matter. Optional trim and ignore-case settings apply to keys and values, with keys revalidated. Missing fields differ from empty strings. Dates are compared as text.
Enable it for selected fields to see decimal changes and signed percentages. A zero old value has no defined percentage and displays N/A. Numeric analysis never changes the underlying string classification. Exported values remain original.