Remove Duplicates

The tool splits the text into individual lines, then iterates through them keeping only the first occurrence of each unique line. Subsequent identical lines are discarded. The order of remaining unique lines is preserved, matching the order they first appeared in the original text.

With case-sensitive matching enabled, 'Apple' and 'apple' are treated as different lines and both are kept. With case-insensitive matching, they are treated as duplicates and only the first occurrence is kept. Enable case-insensitive matching when you want to deduplicate regardless of capitalization.

Trimming whitespace removes leading and trailing spaces and tabs from each line before comparing. This means ' hello ' and 'hello' would be treated as duplicates. This is useful when deduplicating data that may have inconsistent spacing from copy-pasting or CSV exports.

Common uses include deduplicating email lists, cleaning up log files, removing repeated entries from configuration files, consolidating keyword lists for SEO, and eliminating duplicate items in exported data before importing into a spreadsheet or database.

The tool processes text entirely in your browser with no server-side limit. In practice, very large inputs (tens of thousands of lines) may cause a brief processing pause on slower devices. For most typical use cases involving documents, lists, and logs, processing is instantaneous.