YYTOOLS / THE EVERYDAY TOOLBOX

CSV Deduplicator

Remove duplicate CSV rows or match selected columns, keeping first occurrences.

Processed locally · No upload · No sign-up

01 / INPUT

Add your data. Make it useful.

Choose a file or paste text. Your data stays in this browser.

CSV

Up to 5,000 data rows, 200 columns and 100,000 data cells. Input: 0 / 2,000,000 characters. Files must use UTF-8.

CSV delimiter

Match duplicates by

Compare whole rows by default, or read headers and select key columns. Keep the first occurrence and original order.

CSV export settings

Include UTF-8 BOM (helps Excel detect encoding)Prevent formula execution (prefix risky text and quoted headers with an apostrophe)

Text is preserved by default. Excel may interpret CSV values starting with =, +, -, @ and similar prefixes.

Run again after editing input or options.

How to use

Choose a file or paste data. For Excel, select a worksheet.
Adjust options, run the tool, then check the preview or error message.
Review row and column counts, then copy or download the complete result. Run again after editing input.

Match whole rows exactly, or read headers and select key columns. Case and whitespace are significant. Keep the first occurrence and original order, with a count of removed rows.

Previews show up to 50 rows; downloads contain all results. Limits: 5,000 data rows, 200 columns, 100,000 data cells and 5 MiB per file. Combined exported text and text read from Excel are limited to 10,000,000 characters. Exceeding a limit raises an error; data is truncated only when "Truncate long cells" is enabled, with a count shown.

Keep working with your data

CSV Merger ↗CSV Splitter ↗CSV to Excel ↗Browse this category →