Remove duplicate lines
Paste in a list and remove every duplicate line, keeping the first occurrence of each.
One item per line. Emails, URLs, names, anything.
Case-insensitive treats "Apple" and "apple" as the same line; case-sensitive treats them as different.
Duplicates are removed, keeping the first occurrence of each line in its original order.
Frequently asked
Which occurrence of a duplicate line is kept?
The first one. If "apple" appears on line 2 and again on line 9, line 2 is kept and line 9 is removed, and the original order of the remaining lines is preserved.
What happens to the casing of a kept line?
It's left exactly as it was typed. Case-insensitive mode only affects how lines are compared for matching, not how they're displayed in the result.
Are blank lines treated as duplicates of each other?
Yes. Two blank lines are identical lines, so only the first one is kept, same as any other repeated line.
Is this the same as the List Sorter tool?
List Sorter can also remove duplicates, alongside sorting and other cleanup. Use this tool when de-duplication is all you need with a clear before/after count.