Remove Duplicate Lines
Keep only the first occurrence of each line in a text block.
This tool runs entirely in your browser. Your files are never uploaded to a server.
What this tool does
Scans a block of text line by line and removes every repeat, keeping only the first time each exact line appears.
How to use it
Paste your list into the box — the de-duplicated result appears immediately below it, ready to copy. There's no button to click and no setting to configure.
Worked example
Pasting "apple", "banana", "apple", "cherry", "banana" (one per line) produces "apple", "banana", "cherry" — each value kept exactly once, in the order it first appeared.
How duplicates are detected
Each line is compared as an exact string match, tracked in the order lines are read. The first time a line is seen it's kept; every later line with identical text is dropped, and everything else keeps its original position.
Case sensitivity
Comparison is case-sensitive and exact: "Apple" and "apple" are treated as different lines, as are lines that differ only by trailing spaces or a stray tab. Run a separate case-normalization pass first if you need case-insensitive de-duplication.
Limitations
Only whole-line, character-for-character duplicates are removed — near-duplicates like "apple " (with a trailing space) or "Apple" won't be merged. For a single-column CSV export, this works well as long as no extra formatting differs between otherwise-identical rows.
Privacy
The whole list is processed locally in your browser — nothing is uploaded to a server.
Frequently Asked Questions
- Is this case-sensitive?
- Yes, lines that differ only in capitalization, such as "Apple" and "apple", are treated as different lines and both are kept.
- Does it keep the first or last occurrence?
- It keeps the first occurrence of each unique line in the order it appears and removes every later repeat of that exact text.
- Will lines with extra trailing spaces be treated as duplicates?
- No, comparison is exact — "apple" and "apple " (with a trailing space) count as two different lines and neither is removed.
- Can I use it to deduplicate a CSV column?
- Yes, as long as each value is on its own line with identical formatting, pasting a single column works well.
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