Line Deduplicator

A free online text processing tool that remove duplicate lines from text while preserving order. Transform, analyze, and manipulate text instantly in your browser. Duplicate lines creep into text files through copy-paste errors, merged data exports, and imperfect scraping scripts. Mailing lists with repeated addresses, log files with echoed entries, and product catalogs with duplicated SKUs all benefit from instant de-duplication. Removing repeats while preserving original order is something general-purpose editors cannot accomplish without fragile find-replace regex gymnastics. Duplicate detection runs in linear time using a hash set, preserving the first occurrence of each line and removing all subsequent copies. A case-sensitivity toggle lets you treat 'Hello' and 'hello' as identical or distinct. Paste lines that may contain duplicates and the tool instantly returns only unique lines, preserving their original order. Toggle case-sensitive mode if needed. All deduplication happens locally. Your text never leaves your browser — safe for cleaning up customer lists, email addresses, or sensitive records.