Remove Duplicate Lines

Remove Duplicate Lines is a free online tool that instantly deduplicates your text. Paste a list, log file, dataset, or any multi-line text and get clean, unique output in one click. It's perfect for cleaning up email lists, CSV data, code output, keyword lists, server logs, and any text with repeated lines.

Beyond simple deduplication, the tool offers advanced options: case-insensitive matching, whitespace trimming, sorting, occurrence counting, and filtering modes that let you show only duplicates or only unique lines. Everything runs in your browser — nothing is uploaded.

• Remove duplicates: Keep only unique lines with one click
• Keep first or last: Choose which occurrence of a duplicate to preserve
• Case-insensitive matching: Treat 'Apple' and 'apple' as the same line
• Trim whitespace: Ignore leading/trailing spaces when comparing
• Remove empty lines: Strip blank lines from output
• Sort output: Alphabetical (A–Z), reverse (Z–A), or preserve original order
• Count occurrences: See how many times each line appears, formatted as count + tab + line
• Show only duplicates: Filter to display only repeated lines
• Show only unique: Filter to display only lines that appear exactly once
• Live statistics: See total lines, unique lines, duplicates removed, and empty lines in real time
• One-click copy and download

1. Paste your text: Enter or paste multi-line text into the input area on the left.
2. Set your options: Choose matching rules (Ignore Case, Trim Whitespace, Remove Empty Lines), output mode (Remove Duplicates, Show Only Duplicates, Show Only Unique, Count Occurrences), keep preference (First/Last), and sort order.
3. Click Process: The deduplicated result appears instantly in the output area on the right.
4. Copy or download: Use the Copy or Download button to grab your cleaned text.

Input:

apple
banana
Apple
cherry
banana
date
cherry

Output (Remove Duplicates, Ignore Case):

apple
banana
cherry
date

Output (Count Occurrences):

1 apple
2 banana
1 Apple
2 cherry
1 date

• Clean data fast: Deduplicate thousands of lines in milliseconds
• Flexible matching: Case-sensitive or insensitive, with or without whitespace trimming
• Multiple output modes: Don't just remove — analyze your duplicates with counts and filters
• Preserve order: Original line order maintained by default
• Privacy-first: Runs entirely in your browser, nothing stored or transmitted
• Free and unlimited: No sign-up, no limits, no ads blocking your workflow