CSV Cleaner & Deduper

Clean rows, normalize whitespace, remove duplicates, split or merge columns, validate values, and export CSV or Excel.

Upload a messy CSV export and clean it up in one pass: trim whitespace, remove exact-duplicate rows, split or merge columns, validate values against a rule, and reorder or rename headers before exporting the result as CSV or Excel. Built for the kind of spreadsheet cleanup that normally means hours in a formula bar - deduplicating a contact list, splitting a full-name column into first and last, or catching malformed email addresses before an import.

Runs in your browser // nothing is uploaded

Loading tool

How it works

  1. 01

    Upload your CSV file.

  2. 02

    Apply cleanup steps: trim, dedupe, split/merge columns, validate.

  3. 03

    Preview the cleaned data.

  4. 04

    Export as CSV or Excel.

Details

Formats
CSV
Runs
In your browser
Files uploaded
No
Cost per run
Free
Sign-in
Not required
Works offline
Yes, once loaded

Last updated 2026-08-03

Common questions

How are duplicate rows detected?

Rows are compared across every cell after the selected whitespace cleanup is applied. The header is never removed.

Does the file leave my browser?

No. Parsing, cleanup, validation, preview, and exports all run locally.

Can I preview changes before exporting?

Yes - the cleaned data is shown in a live table so you can verify results before downloading.

Is there a row limit?

There's no hard-coded row cap, but very large files are limited by your browser's available memory.

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