Remove duplicate lines
Paste your list: repeated lines disappear and only the first occurrence of each one is kept. You can also ignore upper and lower case.
When you need a list without duplicates
Duplicates creep in everywhere: email lists merged from several spreadsheets (with the risk of sending the same newsletter twice), SEO keyword lists, discount codes, warehouse SKUs, columns exported from a CSV. This tool always keeps the first occurrence of each line, so the original order of your list never changes — only the later repetitions are dropped.
Upper and lower case: when to ignore them
For email addresses it's best to turn the option on: [email protected] and
[email protected] are the same mailbox, so they should count as duplicates. For
product codes, passwords, or technical identifiers, on the other hand, case can be
meaningful — leave the box unchecked. Either way, the line that is kept preserves its
original spelling, completely untouched.