Remove Duplicate Lines
Remove duplicate lines from text, keeping unique lines only.
Frequently Asked Questions
How do I keep the last occurrence instead of the first one?
Turn off `Keep first occurrence`. The tool reverses the working order internally so the last matching line in your original input is the one that survives.
What do case-insensitive and trim comparison actually affect?
They only affect how duplicates are detected. The surviving output line keeps its original text, but the comparison key can be lowercased and/or trimmed before matching.
Can I see which lines were removed?
Yes. Enable `Show removed lines` and the tool will reveal a second textarea listing the discarded lines in the same general order they were removed.
Will it remove blank lines too?
Only if you enable `Remove empty lines too`. Otherwise blank lines are treated like any other line and can remain in the deduped output.
Does this run automatically as I edit the text?
Yes. It recalculates on input changes and option changes, and the button is mainly there if you want a manual action plus a success message.