Remove Duplicate Lines
Paste text and instantly remove duplicate lines. Choose case-sensitive or case-insensitive comparison, optionally trim whitespace before comparing, and remove empty lines. All processing happens in your browser — your text never leaves your device.
How It Works
Paste your text
Paste or type the text containing duplicate lines into the input area.
Choose options
Toggle case sensitivity, whitespace trimming, or empty line removal to control how duplicates are detected.
Copy the result
Unique lines appear instantly in the output. Copy them to your clipboard with one click.
Frequently Asked Questions
How does duplicate detection work?
The tool compares each line to all previous lines. When a duplicate is found, only the first occurrence is kept. The original order of lines is preserved.
What does case-sensitive mean?
When case-sensitive is on (default), 'Hello' and 'hello' are treated as different lines. Turn it off to treat them as duplicates, keeping the first occurrence.
What does trim whitespace do?
Trim whitespace removes leading and trailing spaces from each line before comparing. So ' hello ' and 'hello' would be treated as duplicates.
Is my text sent to a server?
No. All processing happens entirely in your browser using JavaScript. Your text never leaves your device.
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