Remove duplicate lines, use like this
Remove duplicates from input, one per line. You can keep them in the order they first appear, or sort them alphabetically.
Example usage
If you enter apple, pear, and apple on each line, you will be left with one apple and one pear. If you turn on the Remove leading and trailing spaces option, unnecessary spaces will also be removed.
Please note
Case and lowercase letters are treated as different values. If you turn off blank line removal, one blank line will be maintained.
Step-by-step instructions
- Paste a list with one item per line.
- Select the options for removing leading and trailing spaces, removing blank lines, and sorting alphabetically.
- Click Remove Duplicates and copy the results.
Which lines should be considered the same item?
The default setting removes leading and trailing whitespace from each line, leaving the same string only once. Case and lowercase letters and spaces within lines are sensitive. If you do not select a sort, the order of first appearance is maintained. It does not include functionality to interpret columns in a CSV or perform Unicode normalization.
| Input conditions | Results |
|---|---|
| Apple / Pear / Apple (one line each) | Apple / Pear |
| Apple / apple | Two different items |
| Turn on removing leading and trailing spaces | " Apple "Wow "Apple"treated as the same item |
Frequently Asked Questions
Do you also calculate the number of duplicates?
The current tool provides a list with duplicates removed. It does not print frequency tables for each item.
If I turn off blank line removal, will all blank lines be preserved?
Deduplication also applies to blank lines, so only one identical blank line remains.
Are repeated words removed from long sentences?
No. An entire line is treated as one item. Repeated words in sentences are not changed.
Written and operated by: Gu Ja-hyeok · Content review: 2026-09-30 · Error report