Remove Duplicate Lines: Deduplicating Lists in Seconds
Pasting in a list of emails, URLs, or any line-based data and need to get rid of duplicates? This tool removes them while preserving order, with options for case-sensitivity and whitespace handling.
Deduplication is a common spreadsheet headache. Excel can do it, but the menus are buried, and for a quick paste-in / paste-out task, a single-purpose tool is faster. Common cases: cleaning up email lists with accidental copies, building a unique list of URLs from a scrape, removing duplicate entries from a CSV column.
Options that affect duplicates
- •Case-sensitive vs case-insensitive ('Apple' = 'apple'?)
- •Trim leading/trailing whitespace before comparing ('item' = ' item ')
- •Keep first vs last occurrence
- •Sort alphabetically vs preserve original order
Extended FAQ
Does it handle very large lists?
Yes — modern browsers handle hundreds of thousands of lines without issue. Memory is the only practical limit.
Are my pasted lines stored?
No — runs entirely in your browser.