Remove Duplicate Lines
Paste a list or block of text and instantly remove duplicate lines, keeping the original order.
How to use the Remove Duplicate Lines
- Paste your list or text into the box, one item per line.
- Check "Ignore uppercase/lowercase" if "Apple" and "apple" should count as the same line.
- Check "Remove empty lines" to drop blank lines from the result.
- The cleaned result appears live below, along with how many lines were removed.
- Click "Copy result" to copy it, or "Clear" to start over.
How it works
This works by reading your text one line at a time and keeping track of which lines have already appeared, using a lookup set for speed. For example, the list "apple, banana, Apple, banana, cherry" (one per line) becomes "apple, banana, cherry" with the default settings — the second "banana" is dropped, but "Apple" (capital A) is kept since case matters by default. Turning on "Ignore uppercase/lowercase" would also drop "Apple" as a duplicate of "apple". Because comparison uses JavaScript strings directly, accented letters, emoji, and non-Latin scripts are compared correctly rather than being mangled.
Frequently asked questions
Is my text uploaded anywhere?
No — duplicates are removed entirely in your browser with JavaScript. Nothing is sent to a server.
Does this change the order of my list?
No. The first occurrence of each line is kept in its original position — later duplicates are simply dropped, so the order you started with is preserved.
Will "Apple" and "apple" be treated as duplicates?
Only if you check "Ignore uppercase/lowercase." By default, matching is case-sensitive, so "Apple" and "apple" are kept as two separate lines.
Can this handle a very large list?
Yes — it's tested with tens of thousands of lines and stays fast, since it just tracks which lines it has already seen as it goes through the list once.