Text Tools

Remove Duplicate Lines

Clean up a list by deleting every repeated line, keeping the first occurrence.

100% private — everything is processed instantly in your browser, nothing is transmitted anywhere.

How to use Remove Duplicate Lines

  1. 1

    Paste your list

    Put one item per line into the text box.

  2. 2

    Set your options

    Choose case sensitivity, whitespace trimming, and empty-line handling.

  3. 3

    Remove duplicates

    Click the button to clean the list, then copy the result.

About this tool

Lists gathered from multiple sources — email addresses, keywords, spreadsheet exports — often end up with repeated entries. This tool scans your text line by line and removes any line that has already appeared, keeping only the first occurrence in its original position.

You control exactly how matching works: toggle case-sensitivity to decide whether 'Apple' and 'apple' count as duplicates, choose whether to trim whitespace before comparing, and optionally strip out empty lines entirely.

Why use it

  • Keeps the first occurrence, removes the rest
  • Optional case-sensitive matching
  • Trims stray whitespace before comparing
  • Can strip empty lines in the same pass
  • Shows exactly how many lines were removed

Frequently asked questions

Does this keep the first or last occurrence of a duplicate?

The first occurrence is kept, in its original position; every later repeat of the same line is removed.

What does 'case-sensitive' change?

With it off (the default), 'Email@test.com' and 'email@test.com' are treated as the same line. Turn it on if case differences should count as distinct entries.

Will this remove blank lines from my list?

Only if you check 'remove empty lines' — otherwise blank lines are treated like any other line and duplicates among them are still deduplicated.

Can I use this to clean a list of email addresses?

Yes, that's a common use — paste one address per line, and repeated addresses (regardless of extra spaces, if trimming is on) are removed automatically.

Is there a limit on how many lines I can process?

No hard limit — very large lists are only constrained by your browser's available memory.

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