Remove Duplicate Lines
Paste a list, get every line once — optionally sorted
About Remove Duplicate Lines
Mailing lists exported from two systems, keyword lists merged from several tools, log files with the same error repeated hundreds of times — they all need the same fix. Paste the text, and every line appears once in the result, in its original order unless you choose to sort it.
When are two lines the same?
By default, only exact matches count: "Apple" and "apple" are different lines. Tick Ignore case to treat them as one. Trim spaces removes spaces at the start and end of each line, so "apple " with a trailing space is no longer a separate entry — this is the most common reason a list still looks duplicated after cleaning.
apple, Apple, banana , banana, an empty line and cherry become four lines with the defaults (trim on, empty lines removed) and three with Ignore case as well.Natural sorting
A plain alphabetical sort puts "item10" before "item2". This tool sorts numbers the way people expect — item1, item2, item10 — and follows the alphabet of the page language.
Finding the duplicates themselves
Show only lines that were duplicated flips the tool around: instead of a clean list, you get the entries that appeared more than once. It is useful for spotting double registrations or repeated order numbers.