Drop repeated words within each line, keeping the first appearance. Comparison ignores case, so “The” and “the” count as the same word.
the cat the hat the mat red red blue red
the cat hat mat red blue
No. Each line is de-duplicated on its own, so a word repeated on two different lines is kept.
No. This tool runs entirely in your browser — nothing you type or paste is uploaded, logged or stored anywhere.
There is no fixed limit. Very large documents depend on your device’s memory, but ordinary pages and files are handled instantly.