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Duplicate Line Remover

100% Free

Strip duplicate lines from any list, preserving the first occurrence and original order. Case + whitespace toggles, optional alpha sort.

Real-time
Client-Side
Order-preserving
Output (0 lines, 0 removed)
Output appears here…

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<iframe
  src="https://tools.town/embed/duplicate-line-remover/"
  width="100%"
  height="600"
  style="border:none; border-radius:12px;"
  loading="lazy"
  title="Duplicate Line Remover">
</iframe>

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How to Use

  1. 1 Paste lines (one per line) into the input
  2. 2 Toggle case-sensitivity if 'Apple' and 'apple' should match
  3. 3 Toggle 'Trim lines' to ignore trailing whitespace
  4. 4 Optionally sort alphabetically after dedupe
  5. 5 Copy the unique-only result

Features

  • Real-time processing as you type
  • Preserves first occurrence and original order
  • Case-sensitive or case-insensitive match
  • Trim each line before comparing
  • Strip blank lines
  • Optional post-dedupe alphabetical sort

Why it Matters

Email lists, log files, CSV exports, contact lists — they all accumulate duplicates. A reliable de-dupe that respects ordering (so the first 'real' entry wins) and gives you control over case + whitespace beats spreadsheet macros and Python one-liners for the casual cleanup.

★★★★★

Use Cases

Email List Cleanup

Remove duplicate addresses before importing to a mailer

Log File Filtering

Strip repeated error lines to focus on unique issues

Vocabulary Lists

Build deduplicated word lists from raw text

Frequently Asked Questions

Which line is kept when there are duplicates?
The first occurrence in input order. Subsequent matches are dropped.
Why is 'Trim lines' off by default?
Some files (e.g. Markdown) have meaningful trailing whitespace. We default to safe behaviour and let you opt in.
Why does 'apple' and 'Apple' count as different by default?
Default is case-sensitive — most use cases (URLs, paths, codes) are case-significant. Toggle 'Case-sensitive' off to merge them.
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Want to go deeper?

Browse all guides →
How to Use Duplicate Line Remo
deduplicate

How to Use Duplicate Line Remover — Complete Guide

Learn how to remove duplicate lines from any text list quickly using Tools.Town's free Duplicate Line Remover.

8 May 2026

5 min read

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