Remove duplicate lines
Strip repeated lines from a list, keeping the first of each.
What to know
The first occurrence of each line is kept and later repeats are removed, so the original ordering survives. Comparison is exact, meaning trailing spaces and differing capitalisation count as different lines.
Questions
Is anything uploaded to a server?
No. Every tool on this site runs inside your browser using standard web APIs. There is no upload, no account, no logging and no server holding your data afterwards. You can confirm it by opening your browser's developer tools and watching the network tab stay empty while you work.