Unique Line Extractor
Extract Only the Unique Lines From Any Text List
Need to use Unique Line Extractor right now?
Whether you're cleaning a CSV export, a list of email addresses, or a set of URLs pulled from multiple sources, finding duplicates by eye in a long list is slow and error-prone. This tool compares every line and returns only the unique ones instantly, with the option to ignore case differences when two lines only differ by capitalization.
No duplicates removed yet
Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
Who uses this tool?
About Unique Line Extractor
Remove Duplicate Lines takes a block of text — one item per line — and strips out any line that appears more than once, keeping only the first occurrence of each. It's a small, unglamorous task that comes up constantly: cleaning a list of email addresses exported from two different tools before a mail merge, de-duplicating a list of URLs before a crawl, tidying a CSV column you pasted into a text editor, or merging two to-do lists without ending up with the same task twice.
Doing this by hand for anything longer than ten or fifteen lines is tedious and error-prone — you have to scan the whole list repeatedly to catch every repeat, and it's easy to miss a duplicate that differs only in trailing whitespace or capitalization. This tool handles all of that with three toggles. "Case-insensitive" treats "Apple" and "apple" as the same line, which matters for things like deduplicating names or tags where capitalization is inconsistent. "Trim whitespace" strips leading and trailing spaces from each line before comparing, so "banana" and "banana " (with a trailing space) are correctly recognized as duplicates instead of slipping through as technically-different strings. "Remove empty lines" additionally strips out any blank lines in the result, useful when your source list has stray line breaks from copy-pasting out of a spreadsheet or PDF.
The tool preserves the original order of the first occurrence of each line — it doesn't sort your list, just deduplicates it in place — and reports exactly how many duplicate lines were removed, so you have a quick sanity check that something actually changed. Processing happens entirely in your browser using a JavaScript Set for tracking seen lines, which makes it fast even on lists with tens of thousands of lines, and nothing you paste is ever uploaded anywhere.
How it works
- Paste your list. One item per line — email addresses, URLs, tags, to-do items, anything.
- Choose your matching rules. Toggle case-insensitive matching, whitespace trimming, and empty-line removal depending on how strict you want the dedup to be.
- Copy the cleaned list. The deduplicated result appears below with a count of how many lines were removed, ready to copy.
Examples
Deduplicating a fruit list
Input
apple banana Apple cherry banana
Output
apple banana cherry (with "Case-insensitive" on — 2 duplicates removed)