How to Deduplicate a List Quickly
Duplicate entries creep into lists when data is merged from several sources. This guide explains how line-by-line deduplication cleans a list without reordering it.
What is the Remove Duplicate Lines?
Remove Duplicate Lines scans your text line by line and drops every line that has already appeared. The first occurrence of each line stays in its original position, and the tool tells you how many duplicates it removed.
How to use it
- Paste your list into the box, one item per line.
- Click Remove Duplicates.
- Copy the deduplicated list.
Worked example
For the lines 'apple', 'banana', 'apple', 'orange' and 'banana', the output is 'apple', 'banana' and 'orange', followed by the note 'Removed 2 duplicate lines.'.
Should I sort a list before removing duplicates?
You do not need to. Duplicates are found wherever they appear in the list, and the original order is preserved, so sorting is only worth doing if you also want an alphabetical list.
Frequently asked questions
Which copy of a repeated line is kept?
The first one. Later copies are removed, and the remaining lines keep their original order.
Are lines compared exactly?
Yes. Lines that differ by even one character, including extra spaces, count as different lines and are both kept.