Remove Duplicate Lines
Remove repeated lines while preserving the original order.
● Processed locally in your browser unless the page says otherwise.
How duplicates are handled
How duplicate line removal works
This tool removes repeated lines from lists, names, keywords, URLs, product codes, or pasted text while keeping the first occurrence. It is useful for cleaning contact lists, SEO keyword lists, reports, and copied data.
Before removing duplicates, decide whether case, extra spaces, and hidden characters should matter. Lines that look the same may still differ because of spaces or capitalization.
Formula or logic
- Read text line by line
- Normalize each line according to the rule
- Keep the first occurrence
- Remove later repeated lines
Example
If the same URL appears three times in a list, the tool keeps the first copy and removes the later duplicates so the list is easier to use.
Common questions
Will it change the original order?
It usually preserves the order of the first occurrence instead of sorting the list.
Are uppercase and lowercase treated as duplicates?
It depends on the rule. If case is ignored, Apple and apple can be treated as the same line.
Can spaces affect duplicate detection?
Yes. Leading spaces, trailing spaces, or hidden characters can make two lines different.