How duplicate line removal works
Removing duplicates from a list means keeping the first time each line appears and dropping every later copy. The tool reads your text, splits it into lines at each line break, and then keeps a line only if an identical one has not been seen before. The lines that remain stay in their original order, so nothing is shuffled or sorted.
The comparison is exact. "Apple" and "apple" are different lines, and so are "apple" and "apple " with a trailing space, because the characters are not identical. That strictness is useful when case and spacing carry meaning, but it can leave near-duplicates behind that look the same to you. Blank lines are treated like any other line, so only the first empty line is kept and later empty lines are removed.
Common situations where this helps
Lists collect repeats easily. Combining two email lists, merging keyword exports, joining log excerpts, collecting URLs from several sources, or pasting names from different spreadsheets all produce duplicates that you would rather not clean up by hand.
Developers use it to tidy configuration entries, hosts lists, and test data. Writers and researchers use it for reference lists and tag sets. Because order is kept, you can deduplicate a ranked or chronological list without losing its meaning, which a sort-based approach would destroy. If you also want the result alphabetical, run it through Sort Text afterward.
How to remove duplicate lines with this tool
- Paste your list into the Input box on the left, with one item per line. The box starts with a short sample (banana, apple, cherry, apple, date) so you can see how it behaves.
- The Output box on the right updates immediately with the unique lines in their original order. For the sample, apple appears once and the output is banana, apple, cherry, date.
- Replace the sample with your own text, or clear it first.
- Click Copy result to copy the output to your clipboard.
There is no file upload or download button. The work is done in the browser as you type, and the output box is read-only, so copy the result and paste it where you need it.
Mistakes to avoid and limits of this tool
Because matching is exact, tidy the input first if your list has inconsistent capitalization or stray spaces. Two entries that differ only by a trailing space will both survive. You can use Find and Replace with a regular expression to trim such differences before deduplicating.
There is no option to ignore case, trim whitespace, or show how many duplicates were removed, so compare the line counts yourself if you need that figure. Lines are split on the newline character only. If your data is separated by commas or semicolons on a single line, it will be treated as one long line and nothing will be removed until you put each item on its own line.
Very long lists work fine for normal use, though extremely large pastes depend on your browser's memory.