Paste your text to instantly remove duplicate lines, keeping only the first occurrence of each.
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This tool reads your text line by line, keeping only the first occurrence of each unique line and discarding any repeats that appear later, preserving the original order of the remaining lines.
With case-sensitive matching enabled, 'Apple' and 'apple' are treated as different lines. With whitespace trimming enabled, trailing spaces or leading indentation won't prevent otherwise identical lines from being treated as duplicates.
Given the four lines 'apple', 'banana', 'apple', 'cherry', the result keeps only the first occurrence of each: 'apple', 'banana', 'cherry', the second 'apple' is dropped and the original order of the remaining lines is preserved. With case-sensitive matching enabled instead, 'Apple' and 'apple' would each be kept as separate, distinct lines.
Expecting whitespace-only differences to always count as duplicates, trailing spaces or different indentation only get normalized when 'Ignore Leading/Trailing Whitespace' is enabled, with it off, 'apple' and 'apple ' are treated as distinct lines.
Assuming line order is preserved arbitrarily, it isn't, the first occurrence of each unique line is always the one kept, later duplicates are simply dropped, not reordered.
Using this to deduplicate an unordered dataset where order doesn't matter but exact case does, forgetting to disable case-sensitive matching (or leaving it enabled unintentionally) changes which lines count as duplicates.
Blank lines are treated like any other line, if multiple blank lines exist, only the first is kept unless you disable deduplication for that case manually by editing your input.
No, all processing happens directly in your browser, your text is never transmitted anywhere.
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