Remove Duplicate Lines
Remove duplicate lines while preserving order, keep first or last occurrence, and control case, whitespace, blank lines, and Unicode normalization.
Deduplicate lines while preserving the intended record
List deduplication depends on matching rules. Case sensitivity, surrounding whitespace, blank lines, and Unicode normalization can determine whether two visible values are treated as equal.
Keeping the first occurrence preserves the earliest position. Keeping the last occurrence is useful when later rows should replace earlier records.
Remove Duplicate Lines FAQ
Does deduplication preserve list order?
Yes. The selected first or last occurrence retains its relative order in the original list.
What does case-insensitive matching do?
It treats values such as Apple and apple as duplicates while preserving the spelling of the kept occurrence.
Why use Unicode normalization?
Some visually identical characters can have different Unicode sequences. NFC or NFKC normalization can make those sequences comparable.
Continue working with your data
Compare two lists and find values only in A, only in B, shared values, union, or symmetric difference with configurable matching rules.
Delimiter ConverterConvert lists between newline, comma, tab, pipe, semicolon, space, and custom delimiters with trimming, quotes, and deduplication.
Sort List OnlineSort text lines alphabetically, naturally, numerically, by length, or in reverse with trimming, blank-line, and duplicate controls.
Split List Into ChunksSplit a list by items per batch, target batch count, or maximum characters and copy or download each generated chunk.