Find Duplicate Lines
Paste a list of lines and see which ones appear more than once.
Duplicate lines found
Perguntas frequentes
Is the comparison case-sensitive?
Yes, "Hello" and "hello" are treated as different lines, and a line with extra trailing spaces counts as different from one without.
What happens with blank lines?
Empty lines are ignored, even if several appear in a row, they won't be reported as duplicates.
Is my list uploaded anywhere?
No, this runs entirely in your browser with plain JavaScript string comparison. Nothing is sent to a server.