Remove Duplicate Lines
Strip repeated lines out of a list.
Options
Private by design. This tool runs entirely in your browser. Your input is processed on your own device and is not uploaded by DO101.
About the Remove Duplicate Lines
Paste a list and every repeat disappears, keeping the first occurrence and the original order. Case and surrounding spaces can be ignored, which is what usually causes "duplicates" that other tools miss.
How to use it
- 1Paste your list.
- 2Choose whether case and spacing should matter.
- 3Copy the deduplicated result.
What you get
- Keeps the first occurrence and the original order
- Optional case-insensitive matching
- Optional whitespace-insensitive matching
- Counts exactly how many duplicates were removed
- Runs in your browser
Frequently asked questions
Which copy is kept?
The first one. Everything after it in the list is dropped, so the original order is preserved.
Why are my "identical" lines not matching?
Usually a trailing space or a capital letter. Turn on "ignore surrounding spaces" and turn off "case sensitive" and they will match.
Is there a size limit?
Only your browser's memory. Lists of tens of thousands of lines process instantly.
Keep going
People who use this tool usually reach for these next.
Delete blank lines from any block of text.
Sort lines alphabetically, numerically or by length.
Strip double spaces, blank lines and messy formatting.
Live word, character, sentence and reading-time counts.