Remove Duplicate Lines
Delete duplicate lines from any list in one click — with a count of exactly how many were removed.
About this tool
Email lists with the same address three times. Keyword research exports where half the rows repeat. Log files, product SKUs, survey answers — duplicated lines creep into every list, and picking them out by eye is both tedious and unreliable. This tool does it in one click: paste your list, press the button, and every repeated line disappears.
Two details make it trustworthy. First, it keeps the first occurrence of each line and preserves your original order — nothing gets alphabetized or shuffled behind your back. Second, it tells you exactly how many duplicates were removed, so you can sanity-check the result ("removed 47 duplicate lines" from a 500-row export sounds right; "removed 0" tells you your list was already clean).
The two toggles handle the common edge cases: turn off case sensitivity to treat "Apple" and "apple" as the same line, and leave whitespace-trimming on so a line with a stray trailing space still counts as a duplicate of its clean twin. Everything runs locally in your browser — safe for customer email lists and anything else you'd rather not paste into a random website that uploads it to a server.
How to use the Remove Duplicate Lines
- 1Paste your list into the box, one item per line.
- 2Choose your options: case sensitivity, and whether to ignore leading/trailing spaces.
- 3Click Remove duplicates.
- 4Check the removed count, then copy your cleaned list.
Frequently asked questions
Does this tool change the order of my lines?
No. It keeps the first occurrence of each line in its original position and simply deletes later repeats. If you need sorted output, sort it first in your spreadsheet, then deduplicate here.
Are 'Apple' and 'apple' treated as duplicates?
That's your choice. With the case-sensitive option on (default), they're different lines. Turn it off and they're treated as duplicates — the first one encountered is kept.
What about lines that differ only by an extra space?
With 'Ignore leading/trailing spaces' on (default), "apple " and "apple" count as duplicates. The kept line preserves its original spacing. Turn the option off for strict, exact-match comparison.
How large a list can it handle?
Tens of thousands of lines process instantly, because everything runs locally in your browser — there's no upload time and no server limit. Your data never leaves your device.
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