Local data tool

CSV duplicate checker

Compare selected columns, preview repeated records and download a reviewed copy.

Runs in this page. No DeskPlain upload, account or saved history.

Compare records before you remove them.

Small UTF-8 CSV files only, up to 1 MB and 10,000 data rows. This does not open XLSX workbooks or preserve workbook formatting. The original file is never changed.

Choose a CSV file (read locally)

Delimiter

Or paste CSV text

First row contains headings Ignore surrounding spaces in comparison Ignore letter case in comparison

How comparison works

Every nonempty record is read as text. Entirely blank records are excluded and counted separately. Quoted commas, doubled quotes and quoted line breaks are supported. Rows with a different number of fields are rejected so you can review the input rather than silently lose cells.

Optional trimming and case folding affect comparison keys only. Retained original field values stay unchanged until the optional spreadsheet-safe export step. “001” and “1” are different. The tool does not interpret dates or decide which conflicting business record is correct.

Use the full cleanup checklist ↗

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