Remove Duplicate Lines

What does this tool do?

This tool removes duplicate lines from a block of text, keeping only unique lines. It is useful for cleaning up lists, log outputs, CSV data, and any text where repeated entries need to be eliminated.

How to use

• Paste your text into the input area — one entry per line.
• Set the matching options — case-sensitive or case-insensitive, ignore leading/trailing whitespace, and whether to keep the first or last occurrence.
• The deduplicated output and statistics appear immediately below.
• Click Copy to copy the result.

Options explained

• Case-sensitive — Apple and apple are treated as different lines.
• Case-insensitive — Apple and apple are treated as duplicates.
• Ignore leading/trailing whitespace — "apple", " apple ", and "apple " are treated as duplicates. The original text of the kept occurrence is preserved.
• Keep first — the first occurrence of each line is retained.
• Keep last — the last occurrence of each line is retained.
• Remove empty lines — blank lines are excluded from the output.

Example

• Input: apple / banana / apple / orange / banana
• Output (case-sensitive, keep first): apple / banana / orange
• Duplicates removed: 2

FAQ

• Is empty-line removal automatic? No — empty lines are kept by default. Check the option to remove them.
• Is my text sent to a server? No. All processing happens locally in your browser.

Privacy

Your text is processed entirely in the browser. Nothing is transmitted to any server.