Remove Duplicate Lines

What Remove Duplicate Lines does

Remove Duplicate Lines scans a pasted list and strips out repeated entries, leaving only the unique lines behind — in the order they first appeared. It's a quick fix for the kind of messy list that builds up from merging spreadsheets, combining email lists, or copy-pasting from multiple sources.

How to use it

1. Paste your list into the box, one item per line.
2. Click Remove Duplicates to strip out repeats.
3. Click Copy result to copy the cleaned list.

Common uses

• Cleaning a mailing list that's been merged from several exported CSVs.
• De-duplicating a list of URLs before submitting them to a crawler or sitemap tool.
• Removing repeated SKUs or product codes from an inventory export.
• Cleaning up a list of names before a raffle or random draw.
• Tidying keyword lists pulled from multiple SEO research tools.

Good to know

Matching is exact and case-sensitive by default, so "Email@example.com" and "email@example.com" are treated as two different lines — worth checking manually if your list mixes cases. Leading or trailing spaces on a line can also make two otherwise-identical entries look different to the tool, so it helps to run a whitespace cleanup first if your list came from an inconsistent source.

Duplicate entries often creep into lists silently — an export run twice, a spreadsheet merge that didn't check for overlap, or a form that let someone submit more than once. Catching these before they cause a problem (a duplicate email sent twice, a duplicate entry counted twice in a raffle) is usually much easier than untangling the consequences afterward, which is the main reason this kind of cleanup step is worth doing as a matter of habit before using any merged list.