Remove Duplicate Lines
Remove duplicate lines, optionally ignore case
Duplicate scope
Which to keep
Duplicates removed: 0
What is Remove Duplicate Lines?
Remove duplicate lines keeping the first occurrence. Optional case-insensitive matching.
How to Use
- Paste one item per line.
- Enable ignore case if needed.
- Copy the deduplicated output.
Frequently Asked Questions
Which line is kept?
The first occurrence of each unique line.
Related Tools
See Remove Empty Lines and Sort Lines.
How It Works
Modes: remove all duplicates (anywhere) or consecutive only. Keep first or last occurrence. Optional trim-before-compare, ignore case, skip empty lines. Uses Set/scan — O(n).