Duplicate Line Remover
Remove duplicate lines from text.
Overview
Paste in any block of text, and the duplicate line remover keeps only the unique lines. Whether you've got log output with repeated entries, a deduped customer list, or a mailing roster mashed together from two files, one click strips the repeats.
Data analysts cleaning CSV exports, sysadmins parsing log tails, marketers merging email lists, and developers normalizing import files reach for this constantly. It pairs well with Sort Lines if you want a clean alphabetical unique list.
How it works
The tool reads your text line by line, hashes each line, and emits only the first occurrence of any duplicate. Options usually include: keep the first vs. keep the last occurrence, treat lines case-insensitively, trim leading/trailing whitespace before comparing, and ignore blank lines. The original order is preserved by default — sorting is left to Sort Lines.
Examples
Input:
apple
banana
apple
cherry
banana
Output:
apple
banana
cherry
Input (case-insensitive):
Hello
HELLO
hello
Output:
Hello
FAQ
Does it preserve the original order?
Yes. By default, the first occurrence of each line is kept and the rest are dropped, so your remaining lines stay in their original sequence.
What about whitespace differences?
Toggle the "trim whitespace" option to ignore leading/trailing spaces when comparing. Without it, "apple" and "apple " count as different lines.
Can it show me which lines are duplicated?
Some modes offer an "only duplicates" view that flips the operation — useful for auditing where the repeats are coming from.