Duplicate Line Remover
Paste any list, one item per line, and instantly remove duplicate entries — keeping just the first occurrence of each unique line.
How to Use This Tool
Paste your list
One item per line — email addresses, keywords, URLs, anything.
Choose your matching options
Toggle case-sensitivity and whitespace trimming as needed.
Click "Remove duplicates"
Get a cleaned list with only unique entries.
Copy the result
Grab the deduplicated list ready to use.
About the Duplicate Line Remover
Duplicate entries creep into lists constantly — an email list built from multiple exports, a keyword list compiled from several research sessions, or a URL list scraped from different pages that overlap. Manually scanning for and deleting duplicates in a long list is slow and error-prone.
This tool compares every line in your pasted list against every other line and keeps only the first occurrence of each unique value, removing every subsequent duplicate while preserving the original order of the remaining lines.
Two options let you control exactly what counts as a duplicate: case-sensitive matching (so "Apple" and "apple" are treated as different unless unchecked) and whitespace trimming (so "apple " with a trailing space still matches "apple" without one).
Frequently Asked Questions
Does this tool sort my list, or just remove duplicates?
It only removes duplicates — the remaining unique lines stay in their original order from your pasted list. If you also want alphabetical or other sorting, run the result through the Text Sorter tool afterward.
What's the difference between case-sensitive and case-insensitive matching?
With case-sensitive matching on, "Apple" and "apple" are treated as two different, distinct lines. With it off (the default), they're treated as duplicates of each other and only the first occurrence is kept.
Will blank lines be treated as duplicates of each other?
Yes — multiple blank lines in your list are treated as duplicate entries just like any other repeated value, so only the first blank line (if any) will be kept in the result.
Can I use this on a list of full sentences, not just single words?
Yes — the tool works on entire lines regardless of length or content, whether that's single words, email addresses, full URLs, or complete sentences, as long as each item is on its own line.
What happens with "Ignore leading/trailing spaces" turned off?
Then a line with extra spaces at the start or end (like " apple" versus "apple") will be treated as a distinct entry from the version without those spaces, rather than being merged as a duplicate.
Is my list uploaded anywhere when I use this tool?
No — deduplication happens entirely in your browser using JavaScript. Your list is never sent to a server.