Duplicate Line Remover
Remove duplicate lines from a list, with case-insensitive and whitespace-trim options and a removed-count report -- instantly, in your browser.
A duplicate line remover deletes repeated lines from a list — keeping the first occurrence — with options for case-insensitive matching and whitespace trimming. Paste a list, copy the deduplicated result; nothing is uploaded.
How this works
Each line is compared against every line seen so far; the first time a line appears it’s kept, every later repeat of it is removed. Comparison can ignore case and leading/trailing whitespace (both on by default for trimming, off by default for case), but the original line — not a normalized version of it — is always what appears in the result. Order is preserved, and extra blank lines collapse down to at most one.
FAQs
Which duplicate is kept?
The first occurrence. The original formatting of that line is preserved in the output, even if comparison used a trimmed or lowercased version to detect the match.
Can I dedupe case-insensitively?
Yes — turn on the case-insensitive option and "Item" and "item" will be treated as duplicates.
Do trailing spaces make two lines count as different?
Not by default — the trim-before-compare option is on, so "text" and "text " are treated as the same line. Turn it off if you want whitespace differences to count.
Is my text uploaded anywhere?
No. This tool runs entirely in your browser — your text is never sent to a server, uploaded, or stored anywhere.