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Remove duplicate lines
Remove repeated lines while keeping the first occurrence and order.
Use your own or authorized text. Results are escaped text; their content is not executed.
Up to 100,000 UTF-16 units per input. Nothing is saved or sent. CRLF/CR line breaks are interpreted as LF. The first occurrence and original order are kept, using Unicode NFC equivalence. Output uses LF and retains the original whitespace of the first line.
What this tool does
Remove repeated lines while keeping the first occurrence and original order.
How to use it
- Paste one record per line.
- Explicitly choose whether to ignore case or surrounding whitespace.
- Remove duplicates, inspect the counts and copy the result.
Verifiable example
- Input
- Lines a, b, a in that order.
- Expected result
- Lines a, b. Running again leaves that output unchanged.
Limitations to review
- Unicode NFC equivalence is used for comparison; the first occurrence retains its original text.
- Up to 100,000 UTF-16 units. Output uses LF. Options can treat visually different lines as equivalent.
Related tools
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