About the Remove Duplicate Lines
Delete repeated lines while keeping the first occurrence and the original order. Optionally ignore case and surrounding whitespace.
Key features
- Removes repeated lines, keeping the first occurrence
- Original order preserved
- Optional case-insensitive matching
- Optional trimming of leading/trailing spaces
- Optionally remove empty lines too
- Shows how many duplicates were removed
Clean up lists with repeated lines
Merged email lists, combined keyword exports, log files, CSV columns and copied spreadsheets often contain the same line many times. Remove Duplicate Lines keeps each unique line once, in its original order.
Example
apple
banana
Apple
banana
cherry
| Settings | Result |
|---|---|
| Default | apple, banana, Apple, cherry |
| Ignore case | apple, banana, cherry |
Options
| Option | Effect |
|---|---|
| Ignore case | Apple and apple count as the same line |
| Trim whitespace | apple and apple count as the same line |
| Remove empty lines | Blank lines are dropped entirely |
Use cases
- Email and contact lists: remove duplicate addresses before importing into a mailing tool.
- SEO keyword research: merge keyword exports from several tools.
- Log analysis: see each unique error message once.
- Inventory and SKUs: de-duplicate product codes.
- Code: remove repeated import lines or config entries.
Command-line equivalents
awk '!seen[$0]++' file.txt # keeps order, like this tool
sort -u file.txt # sorts and de-duplicates
Related tools
Count how often each line or word appears with the Word Frequency Counter, sort with Sort Text Lines, or remove blank lines with Remove Empty Lines.
How to use the Remove Duplicate Lines
- Type or paste your text into the input box.
- Choose the options you want.
- The result updates instantly as you type.
- Copy the output or download it as a .txt file.