A multi-purpose line processor for plain text: remove duplicate lines while keeping the original order (first occurrence wins), sort lines A→Z or Z→A with an optional numeric-aware mode so that item2 comes before item10, delete empty lines, trim leading and trailing whitespace from every line, reverse the line order, and prepend line numbers. The line counts before and after each operation are shown so you can see exactly how many lines were affected.
Useful for cleaning up lists, log excerpts, CSV columns, email lists or code snippets. Everything runs locally in your browser — your text never leaves your device.