Remove Duplicate Lines
Clean up a list by removing any line that appears more than once.
How It Works
- 1Paste your list, one item per line.
- 2Duplicate lines are removed automatically, keeping the first occurrence.
Features
- Keeps original line order
- Shows how many duplicates were removed
Privacy
All text processing happens instantly in your browser. Nothing you type is ever sent anywhere.
About Remove Duplicate Lines
Duplicate detection works on an exact, character-by-character match between lines, keeping the first time each unique line appears and removing every repeat after it while leaving the surviving lines in their original order. Because the match is exact, two lines that look identical but differ by trailing whitespace, a stray tab, or capitalization (Apple versus apple) are treated as different lines and both survive.
This is most useful for cleaning up list-like data: merging two keyword lists and removing overlap, deduplicating a list of email addresses exported from a spreadsheet, tidying a single-column CSV export, or removing repeated log lines from a chunk of console output.
For the cleanest results, it helps to run text through a whitespace or case normalization step first if duplicates are only differing by spacing or capitalization, since this tool intentionally does an exact match rather than a fuzzy one, which keeps its behavior predictable.