ConvertCSV

Clean Tools

De-duplicate CSV

Remove duplicate rows, optionally keyed by specific columns. Runs locally in your browser — nothing is uploaded for processing.

Input

Paste CSV or upload a file

Options

Output Preview

Result

Run the tool to preview output here.

De-duplicate CSV

De-duplicate CSV removes rows that share the same values. Leave key columns blank to compare entire rows, or name columns to dedupe on a subset.

Everything runs in your browser. File contents are not uploaded to a server for this tool.

Key features

  • Client-side processing
  • Copy or download results
  • Works with paste or upload where applicable

About the CSV to CSV format

The first occurrence of each key is kept; later duplicates are dropped.

Common use cases

  • Cleaning contact lists
  • Removing repeated export rows

How to use this tool

  1. Provide input (CSV, schema, or ciphertext).
  2. Set options if shown, then run the tool.
  3. Copy or download the result.

Tips for best results

  • Sort first if you care which duplicate survives.
  • Preview output before sharing or importing.

Common pitfalls

Keep a copy of the original file — transforms can be hard to reverse.

Frequently asked questions

Is my data uploaded?

No. Processing stays in your browser tab.

For more background on data formats and conversion workflows, read our format guides or browse the converter blog for step-by-step walkthroughs linked to each tool.