>Fafa Dev Tools

Remove Duplicate Lines

Remove duplicate lines from text instantly. Free online deduplication tool with options for case sensitivity and sorting.

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What is Remove Duplicate Lines?

Duplicate lines in text waste space and cause errors in data processing, log analysis, and spreadsheet imports. This tool scans your text and removes any lines that appear more than once, keeping only the first occurrence. It's useful for cleaning up exported data, removing repeated entries in lists, and deduplicating config files or log files.

How to Use

  1. Paste your text containing duplicate lines in the input area
  2. Toggle 'Case sensitive' to control whether 'Hello' and 'hello' count as duplicates
  3. Toggle 'Sort output' to alphabetically sort the unique lines after deduplication
  4. The deduplicated result appears instantly in the output panel

Examples

Remove duplicate entries

Inputapple banana apple cherry banana
Outputapple banana cherry

Deduplicate with sorting

Inputzebra apple apple banana
Outputapple banana zebra

Frequently Asked Questions

Does it keep the original order?

Yes. By default, the tool keeps the first occurrence of each line and preserves the original order. Enable the 'Sort output' option to alphabetically sort the unique lines instead.

What counts as a duplicate?

Two lines are considered duplicates if they are exactly the same, including spaces. With case-insensitive mode off, 'Hello' and 'hello' are different lines. With it on, they are treated as duplicates.

Does it trim whitespace before comparing?

By default, lines are compared exactly as-is, including leading and trailing spaces. If you want to treat ' hello ' and 'hello' as the same, use the Trim Whitespace tool first.