Remove Duplicate Lines
Clean lists in one pass.
Runs on your device
At a glance
- Input:
- Text you type or paste
- Processing:
- Runs locally in your browser
- Privacy:
- Your files stay on your device — nothing is uploaded to a server
About this tool
Order-preserving deduplication for email lists, keyword exports, log lines and CSV fragments — with audit output showing exactly what was removed.
How to use it
- Paste multi-line text.
- Toggle trim/case options if needed.
- Remove duplicates.
- Copy the clean list or download it.
Frequently asked questions
Will my line order change?
No — first occurrences stay in place and later duplicates are dropped, which keeps sorted or curated order intact.
What do the options do?
Trim whitespace treats ' apple' and 'apple' as duplicates. Ignore case does the same for 'Apple'. Show removed lines helps you audit what was cut.
Can it handle large files?
Hundreds of thousands of lines process in well under a second since everything stays local.