Duplicate Line Remover
Chaos in, order out. Instantly clean up mailing lists, database exports, and code snippets by stripping away repetitive clutter.
Configuration
Click "Remove All Duplicates" to generate output
The Art of De-duplication
We live in the age of "Big Data," which often just means "Messy Data." Whether you are merging two customer lists, analyzing server logs, or cleaning up a sloppy CSV export, duplicates are the enemy of accuracy.
Manually checking 5,000 text lines for repeats isn't just boring; it's impossible for a human to do perfectly. Our Duplicate Line Remover handles this computationally, ensuring 100% accuracy in milliseconds.
How It Works
The tool breaks your text block into individual lines. It then iterates through them, adding each unique line to a "Set" (a mathematical collection that only allows unique values). If it encounters a line already in the Set, it discards it.
Understanding the Settings
Case Sensitivity
On: "Apple" and "apple" are kept as two different lines.
Off: "apple" is considered a duplicate of "Apple" and removed.
Trim Whitespace
On: " Hello " becomes "Hello". This prevents invisible spaces from tricking the tool into thinking lines are unique.
Email Marketing
Don't annoy your customers by sending the same newsletter twice. Clean your subscriber list before hitting send.
Developers
Consolidating CSS classes or Import statements? Paste them here to remove redundant definitions instantly.
SEO Pros
Compiling a list of keywords? Remove duplicates to get an accurate count of unique search terms.
Frequently Asked Questions
What happens to empty lines?
By default, our tool includes an option to "Remove Empty Lines." If enabled, blank gaps in your text will be collapsed.
Can I perform "Set Operations"?
This tool does a "Union" of a single list onto itself. If you need to compare two different lists (e.g., find items in List A but not in List B), you would need a "List Diff" tool (coming soon).
Is there a line limit?
Browsers can handle strings up to hundreds of megabytes. Practically, you can process lists with tens of thousands of lines without any lag.
Data Processing
We believe your data is yours. This tool operates effectively offline once loaded (client-side only).