Remove Duplicates
Remove duplicate lines online. Delete duplicate words or lines from text while preserving order. Free duplicate remover tool.
Input Text
Features
- Remove duplicate lines from text
- Remove duplicate words from sentences
- Case-sensitive or case-insensitive deduplication
- Preserve original order
- Count duplicates removed
- Trim whitespace before comparison
Common Use Cases
- Clean up email lists
- Remove duplicate entries from logs
- Deduplicate CSV data
- Clean up repeated words in writing
- Prepare unique lists for import
Deduplication Algorithms and Strategies
Deduplication removes repeated items while preserving unique entries. This tool works line-by-line or word-by-word to eliminate redundancy.
Deduplication modes:
- Line-based - Each line is compared; duplicate lines are removed
- Word-based - Each word is compared; duplicate words are removed
- Case-sensitive - "Apple" and "apple" are different
- Case-insensitive - "Apple" and "apple" are considered duplicates
Order preservation: The tool keeps the first occurrence of each item in its original position, removing only subsequent duplicates. This is different from sort+unique which changes order.
Examples
Input:
user@example.com
test@test.com
user@example.com
→ Removes second "user@example.com"Input: "The the quick brown brown fox"
→ Output: "The quick brown fox"Input:
Apple
apple
Banana
→ Keeps "Apple", removes "apple"Frequently Asked Questions
No! The tool preserves the original order. The first occurrence of each unique item stays in its original position—only subsequent duplicates are removed.
Line deduplication treats each line as a unit. Word deduplication works within lines, removing repeated words while keeping the line structure.
Use case-insensitive for email lists, names, or URLs where "Example.com" and "example.com" should be considered the same. Use case-sensitive for code or where capitalization matters.
Yes, by default! Leading/trailing spaces are removed before comparison, so " apple" and "apple " are treated as duplicates. You can disable this if needed.
The tool shows statistics: original line count, unique line count, and number of duplicates removed. This helps verify the cleanup worked correctly.
💡 Tips
- Before removing duplicates from CSV data, sort it first so related items are grouped together
- Use case-insensitive mode for email lists to catch "User@Email.com" and "user@email.com" as duplicates
- Combine with "Trim whitespace" in Line Tools to ensure clean comparison without invisible space differences
- Export the statistics (before vs after count) to document data cleanup in your workflow