Remove Duplicate Lines
Paste any list and get it back deduplicated — original order preserved, first occurrence kept.
Merged email lists, exported keywords, log files, inventory sheets — combined lists almost always contain duplicates, and removing them by hand or with spreadsheet formulas is fiddly. This tool deduplicates any line-based list instantly: paste it in, and every repeated line after the first is removed while the original order of your list is preserved.
Real-world duplicates are rarely identical, so the options matter: case-insensitive treats "Apple" and "apple" as the same entry, and ignore leading/trailing spaces catches copies that differ only by invisible whitespace — the most common reason a "duplicate" survives a spreadsheet dedupe. A live counter tells you exactly how many lines were removed and kept. Pair it with the line sorter to alphabetize the cleaned list, or the word frequency counter to see which entries repeat most.
How to use the Remove Duplicate Lines
- Paste your list into the input box, one item per line.
- Toggle Case-insensitive if "Apple" and "apple" should count as the same line.
- Keep Ignore leading/trailing spaces on to catch near-duplicates with stray whitespace.
- Copy or download the deduplicated result — the counter below shows how many lines were removed.
Frequently asked questions
Which copy of a duplicate line is kept?
The first occurrence, in its original position. Everything after it that matches is removed, so your list's order is untouched — unlike spreadsheet deduping, which often requires sorting first.
Can it treat lines with different capitalization as duplicates?
Yes — enable "Case-insensitive" and lines that differ only in letter case are considered the same. The kept line retains its original capitalization.
Why does my spreadsheet still show duplicates after deduping?
Usually invisible whitespace: an entry with a trailing space isn't equal to the same text without it. This tool's "Ignore leading/trailing spaces" option normalizes that away when comparing, which catches those stubborn near-duplicates.
Does it remove blank lines?
Only if you enable "Remove blank lines too". By default blank lines are left alone, so list sections separated by empty lines keep their structure.
How big a list can I paste?
Hundreds of thousands of lines are fine — deduplication is a single fast pass that runs locally in your browser, and nothing is uploaded anywhere.