Remove Duplicate Lines Online
Paste your text below and instantly remove all duplicate lines. Options for case sensitivity, sorting and trimming whitespace.
About Remove Duplicate Lines
This tool reads your pasted text line by line and removes any line that has already appeared earlier. It's ideal for cleaning up CSV exports, log files, keyword lists, email lists, and any text where duplicate entries need to be eliminated.
Options include case-sensitive matching (so "Apple" and "apple" are treated as different or the same), trimming leading/trailing whitespace before comparison, sorting the output alphabetically, and removing blank lines.
How to Remove Duplicate Lines
Paste Your Text
Paste the text containing duplicate lines into the input box on the left.
Choose Options
Toggle case-sensitive, trim whitespace, sort lines, or remove empty lines as needed.
Click Remove Duplicates
The deduplicated text appears in the output box on the right with a count of removed lines.
Copy the Result
Click "Copy Output" to copy the cleaned text to your clipboard.
Frequently Asked Questions
When case-sensitive is ON, "Apple" and "apple" are treated as different lines and both are kept. When OFF (default), they are considered duplicates and only the first occurrence is kept.
When enabled, leading and trailing spaces/tabs are stripped from each line before comparing for duplicates. The trimmed version is also written to the output.
Yes, when "Sort lines" is not checked the original order of first occurrences is maintained. Only duplicate (second, third…) occurrences are removed.
The tool works well for files up to several MB. Very large texts (10 MB+) may cause a brief delay since JavaScript processes them synchronously in the browser tab.