Strip duplicate lines from text. Useful for cleaning lists, log files, and CSV data.
Cleaning email lists, deduplicating CSV exports, removing repeated log entries, finding unique URLs from a crawl, or building a unique vocabulary list from text are all common use cases. The tool preserves order by default (keeping the first occurrence) and offers options to sort or to keep the last occurrence instead.
By default, "Apple" and "apple" are different lines. Toggle "Ignore case" to treat them as duplicates.
On Linux/macOS: sort file.txt | uniq removes duplicates after sorting. awk '!seen[$0]++' file.txt preserves order.
Want more detail? Read How to Use Remove Duplicate Lines Tool: Practical Guide and Best Practices.