Remove Duplicate Lines
Remove duplicate lines from text while preserving order
Input Text
Enter text with duplicate lines
7 lines
Output (Unique Lines)
Unique lines will appear here
Option Effects
Case Sensitivity:
Case Sensitive (ON):
"Apple" ≠ "apple" (both kept)
Case Insensitive (OFF):
"Apple" = "apple" (duplicate removed)
Whitespace Trimming:
Trim (ON):
" apple " = "apple" (duplicate removed)
No Trim (OFF):
" apple " ≠ "apple" (both kept)
Occurrence Preference:
Keep First (ON):
First "apple" is kept, others removed
Keep Last (OFF):
Last "apple" is kept, others removed
Quick Examples
Use Cases
- • Clean up email lists
- • Remove duplicate URLs
- • Deduplicate log entries
- • Clean data exports
- • Process survey responses
- • Merge and clean lists
- • Database cleanup
- • File list processing
Features
- • Preserves original order
- • Case-sensitive option
- • Whitespace trimming
- • Choose first or last occurrence
- • Real-time statistics
- • Copy and download results
- • Handles large lists
- • Empty line handling
Tips
- • Enable trim to ignore spacing differences
- • Disable case sensitivity for names/emails
- • Keep first occurrence preserves original order
- • Use for cleaning imported data
- • Great for merging multiple lists
- • Works line-by-line (each line = one item)
How It Works
The tool processes your text line by line:
- Reads each line
- Optionally trims whitespace
- Compares with seen lines
- Keeps unique lines only
- Preserves original order
The comparison respects your chosen options for case sensitivity and whitespace handling.