Deduplicate CSV Data

Deduplicate CSV Data removes duplicate rows from your CSV file with live preview, file import, and export support. Fast, browser-based cleanup.

Paste your input above or import a file below.
No file chosen
Supported file types: .txt, .csv, .log
Total characters: 0
Options
Trim fields
Case-sensitive
Keep first instance only

How to Use:

  • Paste your CSV data into the CSV Input box, or use the Choose File button to upload a .csv, .txt, or .log file.
  • The first line is always treated as the header and stays at the top of the output.
  • The tool automatically removes rows that match earlier ones based on your selected rules.
  • Use the Options panel to control how duplicates are detected:
    • Trim fields: Removes leading and trailing spaces from each value before comparing.
    • Case-sensitive: Treats uppercase and lowercase as different (Alice ≠ alice).
    • Keep first instance only: Keeps the first match and removes duplicates that follow.
  • Output updates live as you type or change settings.
  • The deduplicated content appears in the Deduplicated Output area with a Total characters count below it.
  • Click Copy Output to copy the cleaned CSV to your clipboard.
  • Use Export to File to download the result as a .csv file.
  • Click Clear All to reset everything inputs, toggles, and file status.

What Deduplicate CSV Data can do:

This tool scans your CSV line by line, removing exact duplicates based on your rules. You can trim values to normalize spacing, make it case-insensitive, and choose whether to keep just the first version of any repeated row. It’s great for cleaning exports, de-duping merge lists, or prepping files for import where unique records matter. No scripts or desktop software needed it’s fast, reliable, and runs entirely in your browser.

Example:

Before:

name,age,city
Alice,30,New York
Bob,25,Los Angeles
Alice,30,New York
Charlie,22,Chicago
Bob,25,Los Angeles

After:

name,age,city
Alice,30,New York
Bob,25,Los Angeles
Charlie,22,Chicago

Common Use Cases:

Perfect for removing duplicates from mailing lists, contact sheets, or any exported table with repeated entries. It’s also ideal for prepping clean data before import into a database, CRM, or analytics tool.

Useful Tools & Suggestions:

Run Find Incomplete CSV Records first to make sure blanks aren’t being counted as duplicates. And after deduping, use Count CSV Rows to confirm how much was actually removed.

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