Remove Duplicate Lines|Options
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Input
e.g. apple Banana apple banana cherry
Output
e.g. apple Banana banana cherry
Chars: 0
Words: 0
Sentences: 0
Paragraphs: 0
Reading: < 1m
Speaking: < 1m
Total lines: 0
Unique: 0
Duplicates: 0

Remove Duplicate Lines Online — Delete Repeated Lines & Keep Unique Entries

Have a list with repeated entries you need to clean up? This free tool removes duplicate lines from your text, keeping only unique entries while preserving the original order.

How to Use This Tool

  1. Paste your text — Copy your list or text with duplicate lines and paste it into the input panel.
  2. Configure options — Choose whether comparison should be case-sensitive and whether to trim whitespace before comparing.
  3. Review the output — The deduplicated text appears in the output panel with duplicate lines removed.
  4. Copy the result — Click Copy to grab the unique-lines-only version of your text.
  5. Chain with other tools — With Auto-fill enabled, your output automatically carries over when you open another tool from the sidebar. Use the back and forward arrows to undo navigation and restore your previous tool state including all options.

Features

Preserves Original Order

The first occurrence of each line is kept in its original position. Only subsequent duplicates are removed.

Case-Sensitive Option

Choose whether "Hello" and "hello" should be treated as duplicates or as different lines.

Whitespace Trimming

Optionally trim leading and trailing whitespace before comparing lines, so lines differing only by spaces are treated as duplicates.

Handles Large Lists

Efficiently processes lists with thousands of lines without performance issues.

Instant Results

Duplicates are removed in real time as you paste or modify your text.

Complete Privacy

All processing happens locally in your browser.

Auto-fill Pipeline

Enable Auto-fill to carry your output to the next tool. Navigate back and forward with full state restoration — input, output, and all settings are preserved.

Real-World Use Cases

1

Deduplicate a mailing list

Paste a list of email addresses or names and instantly remove duplicates to ensure each entry appears only once.

2

Clean up repeated log entries

Application logs often contain repeated error messages. Remove duplicate lines to see only unique entries and identify distinct issues.

Frequently Asked Questions

Does it preserve the original order of lines?
Yes. The first occurrence of each unique line is kept in its original position. Only the second, third, and subsequent duplicates are removed.
Is the comparison case-sensitive?
By default, yes. "Apple" and "apple" are treated as different lines. You can toggle case sensitivity off to treat them as duplicates.
Does it trim whitespace before comparing?
You can enable whitespace trimming so lines like " hello " and "hello" are considered duplicates. Without trimming, trailing or leading spaces make lines different.
Can it handle very large lists?
Yes. The tool processes text in your browser and can handle lists with tens of thousands of lines on modern devices.
Will it remove empty lines?
Duplicate empty lines will be reduced to one empty line. To remove all empty lines entirely, use the Remove Empty Lines tool.
Is my data private?
Yes. All processing runs locally in your browser. Nothing is sent to a server.

Related Tools

Sort Lines

Sort lines alphabetically, numerically, or randomly.

Remove Lines

Delete lines by pattern, regex, or blank line rules.

Remove Whitespace

Trim and collapse extra spaces and tabs.

Extract Emails/URLs

Pull out email addresses and URLs from text.

Find & Replace

Search and replace text with regex support.

All text processing happens directly in your browser. Your text is never sent to any server, stored, or shared with third parties. This tool is completely private and secure.