Remove Duplicate Lines
Remove duplicate lines from text with multiple modes. Keep first, last, or remove all duplicates.
Input Text
Keep first occurrence, remove later duplicates
Result
4 Modes
First, last, none, consecutive
Case Options
Sensitive or insensitive
Statistics
See what was removed
100% Private
No data stored
Why Remove Duplicate Lines?
Duplicate lines often appear in data exports, log files, email lists, and code. Cleaning them up improves data quality, reduces file size, and makes information easier to process. Our tool offers multiple deduplication modes to handle different scenarios.
Deduplication Modes Explained
| Mode | Behavior | Best For |
|---|---|---|
| Keep First | Preserves first occurrence, removes later duplicates | Most common use case |
| Keep Last | Preserves last occurrence, removes earlier duplicates | When latest entry matters |
| Remove All | Removes all lines that appear more than once | Finding truly unique entries |
| Consecutive Only | Only removes duplicates that are adjacent | Cleaning sorted lists |
Common Use Cases
- Email Lists: Remove duplicate email addresses before sending campaigns
- Data Cleanup: Deduplicate CSV exports or database dumps
- Log Analysis: Remove repeated log entries for cleaner analysis
- Code Cleanup: Find and remove duplicate import statements
- Content Editing: Remove accidentally repeated paragraphs or lines
Frequently Asked Questions
What's the difference between the modes?
Keep First/Last preserves one copy. Remove All deletes everything that appears more than once. Consecutive Only only removes adjacent duplicates.
What does case sensitive mean?
When enabled, 'Apple' and 'apple' are different. When disabled, they're treated as duplicates.
Can I sort the output?
Yes! Enable 'Sort result A-Z' to alphabetize the deduplicated lines.
Is my data stored?
No! All processing happens in your browser. Your data never leaves your device.