Remove Duplicate Lines
Delete repeated lines from a list, keeping order.
Remove Duplicate Lines
This tool runs entirely in your browser. Your files never leave your device.
How to use
- 1Paste your list with one item per line.
- 2Choose whether case and surrounding spaces should matter.
- 3Copy the deduplicated list from the output box.
About this tool
This tool removes lines that appear more than once in your text, keeping either the first or the last occurrence and preserving the original order of the remaining lines. It compares whole lines exactly by default, with options to ignore letter case and trim stray spaces before comparing, so "Apple" and "apple " can be treated as the same line if you want. It's built for line-based data — one item per line — rather than for finding repeated words or phrases inside a paragraph.
Benefits & use cases
- Clean up an email or mailing list before importing it into another tool.
- Deduplicate a keyword research export so each keyword appears once.
- Collapse repeated lines in a server or application log file.
- Merge two contact or subscriber lists without ending up with duplicates.
- Tidy a list of URLs or file paths before processing them further.
Frequently asked questions
Is the original order kept?
Yes. Lines stay in their original order; only later duplicates are dropped.
Does it sort the lines?
No. Use the Text Sorter tool if you also want the list sorted.
What counts as a duplicate — the whole line, or just part of it?
The whole line, compared exactly unless you enable "Ignore case". Two lines with different trailing spaces are only treated as duplicates if "Trim spaces around each line" is also on.
Does it handle very large lists?
It works entirely in your browser's memory, so it comfortably handles lists of thousands of lines. A multi-million-line file may be slower, since the whole list needs to be held in memory at once.