Writing
Remove Duplicate Lines
Clean up lists, logs, and exports by removing repeated lines. Choose to keep the first occurrence of each line or keep only lines that appear exactly once, and optionally compare lines case-insensitively or after trimming whitespace. The summary shows how many lines were removed and how many remain.
Examples
Input · Keep-first mode, case-sensitive.
apple Apple banana apple
Output
apple Apple banana
How to use Remove Duplicate Lines
Paste your lines
Drop in any list or block of text with repeated lines.
Pick a mode
Keep the first occurrence of each line, or keep only lines that appear once.
Refine matching
Toggle case-insensitive and trim options to control what counts as a duplicate.
Why use this tool
Two modes: keep-first or unique-only
Optional case-insensitive matching
Optional whitespace trimming before comparison
Live summary of removed and remaining lines
Frequently asked questions
Keep-first keeps the first time each line appears; keep-unique-only keeps lines that occur exactly once and drops anything repeated.
Yes. Enable the case-insensitive and trim toggles to treat lines that differ only by case or surrounding whitespace as duplicates.
Discussion
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