Remove Duplicate Lines
Remove repeated lines and keep only the unique ones, in order.
How to use the Remove Duplicate Lines
- Paste your list, one item per line.
- The unique lines appear on the right — copy them out.
About the Remove Duplicate Lines
Paste a list and get back only the lines you have not already seen. The first occurrence of each line stays exactly where it was and every later repeat is dropped, so your original order survives — which matters when the order carries meaning, as in a ranked keyword list, a log, or a playlist.
Matching is exact and case-sensitive. “Apple” and “apple” are different lines and both survive. So do “apple” and “apple ” — one trailing space makes two identical-looking lines different, and this is by far the most common surprise with any dedupe tool. If a line you expected to disappear is still there, invisible whitespace is almost always the reason. Run the list through the extra spaces remover first, which trims every line, and then deduplicate.
Blank lines are handled like any other line: the first empty line is kept and every later one is removed, so a double-spaced list comes back with a single gap near the top rather than none at all. To strip them all out, use the empty lines remover. Everything runs in your browser — nothing is uploaded, which makes this usable for customer emails, internal data and anything else you would not paste into a random website.
Frequently asked questions
Is it case-sensitive?
Yes. "Apple" and "apple" are treated as two different lines and both are kept. To ignore case, convert the whole list to lowercase first with the case converter, then deduplicate.
Which copy of a duplicate is kept?
The first one. Every later repeat is removed, and the surviving lines stay in their original order — nothing is sorted or moved.
Why are two lines that look identical not being merged?
Almost always trailing whitespace. A line ending in a space is not equal to the same line without it, and you cannot see the difference on screen. Trim the lines first with the extra spaces remover, then deduplicate.
What happens to blank lines?
They are deduplicated like everything else, so the first blank line survives and all the others are removed. If you want no blank lines at all, use the remove empty lines tool instead or afterwards.
Does it sort the output?
No — original order is preserved deliberately. If you want the result alphabetical, run it through the sort lines tool afterwards.