Remove Duplicate Lines (Free, Keep Unique)

Why Remove Duplicate Lines?

Duplicate lines appear when merging data sources, combining log files, or processing CSV exports. Removing duplicates keeps only unique lines—essential for cleaning email lists, deduplicating URLs, consolidating config keys, or preparing datasets for analysis without skewed counts.

Common Use Cases

• Email lists: Deduplicate contact lists before sending newsletters or campaigns
• URL lists: Remove duplicate URLs from sitemaps, link exports, or crawl results
• Log analysis: Deduplicate repeated log entries to count unique events
• CSV cleaning: Remove duplicate rows from database exports or spreadsheet merges
• Config files: Eliminate duplicate keys or settings from .env or config files
• Data merging: Combine multiple lists (keywords, IPs, domains) and remove duplicates

Why This Tool?

• Exact matching: Removes only lines that match character-for-character
• Preserves order: Keeps first occurrence and removes subsequent duplicates
• Instant deduplication: Paste text and remove duplicates in milliseconds
• 100% client-side: Your data never touches our servers—runs in your browser
• Free forever: Unlimited deduplication with no line limits

Pro tip: After removing duplicates, use Sort Lines to organize alphabetically or Word Counter to check how many unique lines remain.