Remove Duplicate Lines
Remove duplicate lines from your text. Optionally ignore case or trim whitespace before comparing.
How to Remove Duplicate Lines
Paste your text into the input area with one item per line, then click Remove Duplicates. The tool scans every line and removes any that have already appeared, keeping only the first occurrence. You can toggle Case Sensitive matching off to treat 'Apple' and 'apple' as the same line, which is useful for deduplicating lists of names, tags, or email addresses that may have inconsistent capitalization. The Trim Whitespace option strips leading and trailing spaces from each line before comparing, catching duplicates that differ only by invisible whitespace. After processing, you see the deduplicated result along with a count of how many duplicate lines were removed.
Common Uses for Duplicate Removal
This tool is invaluable when working with data exports, email lists, log files, keyword lists, and CSV columns pasted as line-separated values. Marketers use it to clean up mailing lists and keyword research exports. Developers use it to deduplicate configuration entries, environment variables, or lines from log output. Students and researchers use it to clean up bibliography references or survey responses. Because the tool preserves the original order of first occurrences, your list stays organized the way you originally had it. Combined with the Sort Lines tool, you can quickly clean and alphabetize any list for further processing.