This runs in your browser. Nothing is uploaded.
About Duplicate line remover
Remove duplicate lines from a list while keeping the first occurrence — optional case-insensitive mode.
Deduping a pasted list is a job people still dump into Excel. Paste lines here, drop exact duplicates, keep original order with first-wins semantics. Optional case-insensitive mode treats 'Apple' and 'apple' as the same line.
Blank lines and spacing are yours to clean first if that matters — the tool compares lines as they stand after your paste. Nothing is sent to a server; large pastes stay in memory in this tab.
Sorting is a different page: line sorter orders alphabetically or numerically. Word counter tallies without rewriting. Diff compares two whole texts.
How to use Duplicate line remover
- 1Paste your newline-separated list.
- 2Toggle case-insensitive dedupe if you need it.
- 3Copy or replace with the unique lines.
What it won't do
- Whole-line duplicates only — not fuzzy near-matches.
- In-tab only; no file watchers.
Common questions
Is order preserved when removing duplicates?
Yes. The first time a line appears, it stays; later copies are dropped.
Does trimming whitespace count in the comparison?
Comparison uses the line content as pasted. Trim in your editor first if trailing spaces cause false uniques.
Is there a size limit?
Practical browser memory is the limit. This is not a gigabyte log processor.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation