DocomintRemove Duplicate Lines
Delete repeated lines from a list, keeping only the first occurrence of each.
Built for cleaning up an email list, a keyword list, or any export that ended up with the same line pasted in twice — order is preserved, so the first time each line appeared is where it stays.
Example: A list of 200 email addresses exported from two separate signup forms often has 15-30 duplicates — this strips them down to a clean, unique list in one paste.
How it works
- Paste a list with repeated lines
- Duplicates are removed instantly, on your device
- Copy the deduplicated list
Frequently asked questions
Does this preserve the original line order?
Yes — the first occurrence of each line stays in its original position; only later repeats are removed.
Is my text uploaded anywhere?
No — Remove Duplicate Lines runs entirely in your browser using JavaScript/WebAssembly. Your text is never sent to a server.
Is duplicate detection case-sensitive — would 'Apple' and 'apple' count as the same line?
Yes, comparison is case-sensitive by default, so 'Apple' and 'apple' are treated as different lines. Run Case Converter first if you need a case-insensitive cleanup.