Remove Duplicate Lines
Paste a list or block of text — remove repeated lines instantly, with an option for case-insensitive matching.
Blank lines are always kept. The first occurrence of each line is kept; later repeats are removed.
Result
Remove Duplicate Lines — Clean Up Lists Instantly
This duplicate line remover strips repeated lines from any list or block of text, keeping only the first occurrence of each unique line.
Need to sort the result afterward? Try sort alphabetically, or run everything through the text cleaner in one pass.
Common uses
- Email & contact lists — remove duplicate addresses before a mail merge or import.
- Keyword & URL lists — clean up scraped or exported data for SEO or research.
- Code & config files — deduplicate lines in CSV exports, log files, or dependency lists.
- Survey & form data — quickly spot and remove accidental duplicate entries.
Case-sensitive vs. case-insensitive
"Remove Duplicates" treats "Apple" and "apple" as different lines. "Remove Duplicates (case-insensitive)" treats them as the same line and keeps only the first version encountered. Blank lines are always preserved in both modes.
All processing runs entirely in your browser. Your text is never sent to any server. See also: remove extra spaces · FAQ.
Frequently Asked Questions
The first occurrence of a line is always kept; any later repeats of that same line are removed from the result.
“Remove Duplicates” is case-sensitive, so “Apple” and “apple” are treated as different lines. “Remove Duplicates (case-insensitive)” treats them as the same line and keeps only the first one.
No — blank lines are preserved as-is in both modes. Use the text cleaner if you also want to strip empty lines.
Yes, it runs entirely in your browser with no size limit imposed by the tool itself — very large pastes are only limited by your browser's own textarea performance.