List Deduplicator
Remove duplicate emails.
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Quick Tip
Paste your list in whatever shape it arrived — numbered, CSV, a table paste, or text with names mixed in.
About This Tool
Why use List Deduplicator?
Paste a messy list and get back the unique email addresses in it. Rather than comparing lines, the tool matches addresses with a pattern anywhere in the text, so numbered lists, CSV rows, pasted table cells and text with names and phone numbers mixed in all work — everything that is not an address is simply ignored.
Addresses are lowercased before comparison, which is what makes the deduplication actually work: John@Example.com and john@example.com are the same mailbox, and a plain unique filter would keep both. The counts before and after are shown, so you can see how much of your list was duplicated — and duplicates matter more than they look, because sending the same message twice to one person is a fast route to a spam complaint.
Key Benefits
Handles messy input
Addresses are found anywhere in the text, so numbering, CSV commas and mixed-in names do not need cleaning out first.
Case-insensitive matching
Addresses are lowercased before comparison, so the same mailbox written two ways is caught rather than kept twice.
Counts shown
The original and unique totals are both displayed, so you can see how much duplication was in the list.
How to use List Deduplicator
- 1
Paste your list in whatever shape it arrived — numbered, CSV, a table paste, or text with names mixed in.
- 2
Process; addresses are matched anywhere in the text and lowercased for comparison.
- 3
Compare the original and unique counts.
- 4
Copy the clean list into your sending tool.
Best use cases
Merge two contact lists without mailing anyone twice.
Clean a list exported from a form or a spreadsheet.
Pull the addresses out of a block of pasted text.
Check for duplicates before importing into a sending tool.
List Deduplicator FAQs
Does it handle different capitalisation?
Yes. Addresses are lowercased before comparison, so John@Example.com and john@example.com are recognised as the same mailbox and kept once.
Does my list need to be one address per line?
No. Addresses are matched anywhere in the text, so numbered lists, CSV rows and pasted table cells all work without cleaning up first.
Are Gmail dot and plus variants treated as the same address?
No. john.smith@gmail.com and johnsmith+news@gmail.com reach the same inbox at Gmail, but they are different addresses as written and are kept separately. Normalise those yourself if it matters.
Why do duplicates matter so much?
Sending the same message twice to one person is one of the quickest ways to get marked as spam, and complaint rate is a signal that affects delivery for your whole list.
Related Email Tools
More free email tools that work well alongside list deduplicator.