🧹 Remove Duplicate Lines
Paste a list, get it back with duplicates removed, first occurrence kept, order preserved.
1 duplicate line removed
How the remove duplicate lines works
Each line is compared against every line seen before it; repeats are dropped and the first occurrence kept, so your original order survives. "Ignore case" treats Apple and apple as the same line; "ignore spaces" disregards invisible leading/trailing whitespace, the most common reason two identical-looking lines both survive. Comparison is exact by default, character for character; the two options relax it, case folding maps letters to a common case before comparing, and trimming removes leading and trailing whitespace so only the visible content decides a match.
Typical jobs: cleaning email lists, keyword lists, log extracts and spreadsheet columns pasted as text. For a sorted unique list, run this tool first, then the sort-lines tool, or vice versa; the result is the same set.
Frequently asked questions
Does it keep the first or last occurrence?
The first, everything after a line’s first appearance is removed, and the surviving lines keep their original order.
Why do two identical-looking lines both remain?
Almost always invisible trailing spaces or different capitalization. Enable both options and they will merge.
Can I deduplicate comma-separated values?
Put each value on its own line first, the find & replace tool converts ", " to line breaks in one step, then dedupe.
Is there a size limit?
Practically no, tens of thousands of lines process instantly, since everything runs locally in your browser.
Does it change the lines it keeps?
No, surviving lines are returned exactly as you pasted them, including their original capitalisation and spacing. The options only affect which lines count as duplicates, not how the kept lines look.
How can I tell how many duplicates were removed?
Compare the line count before and after, the difference is the number of duplicate lines dropped. The output keeps the first occurrence of every distinct line.
Is my list uploaded anywhere?
No. Lists often contain emails or customer data, exactly why this tool never transmits anything.