Category: Developer tools

CSV Deduplicator

System ideaMissing a tool?

Remove duplicate rows from CSV or delimited data

Paste CSV, semicolon, tab or pipe-separated data and remove duplicate rows, matching on the whole row or on the columns you choose. Runs entirely in your browser.

1 duplicate row(s) removed, 3 kept.

Deduplicated CSV
name,email,team
Ada Lovelace,ada@example.com,Blue
Grace Hopper,grace@example.com,Green
"Doe, John",john@example.com,Green

Everything on this page is processed in your browser. Nothing is uploaded.

What this tool does

Exported spreadsheets and merged CSV files frequently end up with the same row repeated, sometimes exactly, sometimes only matching on a key column like an email address or ID. This tool parses quoted fields correctly for the delimiter you choose, keeps the header row in place, and removes every row after the first one that matches on the whole row or on the key columns you name by header or position.

How to use it

  1. Paste your CSV or delimited data.
  2. Choose the delimiter and whether the first row is a header.
  3. Optionally name key columns by header or position to match on, then copy the deduplicated result.

Privacy

This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.

Frequently asked questions

Is my data uploaded anywhere?
No. Parsing and deduplication happen in JavaScript in your browser; the data never leaves your device.
What happens to quoted fields containing the delimiter?
They are parsed correctly as a single field and re-quoted in the output, the same way the other CSV tools on this site handle them.
How do I match on more than one column?
List the column headers or 1-based positions separated by commas, for example "email,team" or "1,3"; leave the field empty to match on the entire row.