How to use the Remove Duplicate Lines
- Paste your list — emails, keywords, URLs, names — one per line.
- Choose whether “Apple” and “apple” count as the same line.
- Keep “Trim spaces” on so invisible trailing spaces do not hide duplicates.
- Copy the cleaned list; the counter shows how many lines were removed.
Why duplicates survive other tools
Most “duplicates” that slip through are not exact matches: a trailing space from a spreadsheet, different capitalization, or Windows versus Unix line endings. This tool normalizes line endings automatically and lets you ignore case and surrounding whitespace, so Apple, apple and APPLE can be treated as one line.
Order is preserved
Unlike sorting and then removing adjacent duplicates, this keeps your list in its original order and keeps the first time each line appears. That matters for ranked keyword lists, priority queues and anything where position means something.
Example: b, a, B, b, a with “ignore case” becomes b, a.
Frequently asked questions
Does it keep the first or last duplicate?
The first. Every later repeat of a line is removed, and the remaining lines keep their original order.
How do I remove duplicates in Excel instead?
In Excel, use Data → Remove Duplicates, or =UNIQUE(A:A) in Excel 365. This tool is faster for a one-off list you have copied from anywhere, and it does not require a spreadsheet.
Can it handle large lists?
Yes. Hundreds of thousands of lines are processed in well under a second, entirely in your browser.
Are blank lines removed?
Only if you turn on “Remove empty lines”. By default blank lines are kept so paragraph spacing is not lost.