Remove Duplicate Lines

The first occurrence of each line is kept; later duplicates are removed, preserving your original line order.

Yes — enable "Case insensitive" so "Apple" and "apple" are treated as duplicates.

No. Blank lines are kept as-is and never deduplicated against each other, so your paragraph spacing is preserved. If you'd rather strip every empty line, turn on "Remove blank lines".

Yes — two lines that differ only by a trailing space are treated as different. Trim the whitespace first if you want them matched, which is a common gotcha with copied spreadsheet columns.

Lists of tens of thousands of lines process in well under a second. Everything runs in your browser's memory, so the practical ceiling is your device rather than a fixed limit.

No. Order is preserved deliberately, since sorting would destroy meaningful sequences like logs or rankings. Use the text sorter if you also want the result sorted.

The counter reports how many lines were removed, so you can tell at a glance how much overlap there was between the entries.

Yes, it's one of the most common uses. Paste one address per line and turn on case-insensitive matching, since email addresses are not case-sensitive in practice.

No. It works line by line, so a repeated word inside a single line is left alone. Split your text so each item sits on its own line first.

No. Everything runs locally in your browser — nothing is sent to a server.