A merged mailing list, a scraped set of keywords, a pasted log file — anywhere you combine lists from more than one source, duplicate lines follow. Opening Excel just to deduplicate a list you're going to paste right back out as plain text is more steps than the job needs.
What counts as a "duplicate" here
This matters more than it sounds: our Remove Duplicate Lines tool treats two lines as duplicates only if they match exactly, character for character. That means:
john@email.comandJohn@Email.comare treated as different lines (case matters).- A line with a trailing space is treated as different from the same line without one — invisible, but real to an exact-match comparison.
If your list has inconsistent casing or stray trailing spaces (extremely common in anything copy-pasted from a website or a PDF), run it through Case Converter first (lowercase everything) to catch case-only duplicates that would otherwise slip through as "different" lines.
What order you get back
The result keeps the first occurrence of each line and preserves the original order — it doesn't alphabetize or reshuffle your list, it only removes the repeats. If you also want the result sorted, run it through Text Sorter afterward.
Using the tool
Paste your list, and you'll get the deduplicated result plus a count of exactly how many duplicate lines were removed. Try it here: Remove Duplicate Lines.