Free tool
Remove duplicate emails from your list
Paste your email list below to remove duplicates instantly. Everything runs in your browser, so your list never leaves your computer.
0 entries parsed
0 unique kept
0 duplicates removed
0 invalid dropped
A clean email list is the foundation of every successful campaign. When you remove duplicate emails before sending, you avoid emailing the same person twice, keep your bounce rate low and protect your sender reputation. This free duplicates remover accepts lists separated by new lines, commas, semicolons or spaces, removes repeated addresses, optionally drops invalid entries, and hands you back a tidy list ready for your next mail merge.
How to remove duplicate email addresses
- 1
Paste your email list into the box on the left. New lines, commas, semicolons and spaces all work as separators.
- 2
Choose your options: ignore letter case, trim spaces, drop invalid addresses or sort the result alphabetically.
- 3
Click "Remove duplicates".
- 4
Review the stats to see how many entries were parsed, kept, removed as duplicates or dropped as invalid.
- 5
Copy the clean list or download it as a .txt file, then import it into your Google Sheet for your next campaign.
Frequently asked questions
Is my email list uploaded to a server?
No. This tool runs entirely in your browser using JavaScript. Your list is never sent over the network, stored or logged anywhere, which makes it safe to clean even sensitive contact lists.
Why should I remove duplicates before sending a campaign?
Sending the same message twice to one person looks careless and increases the odds of a spam complaint or an unsubscribe. Duplicates also inflate your sending volume, which can push you over Gmail's daily limits faster than necessary.
Are john@example.com and John@Example.com the same address?
In practice, yes. The domain part of an email address is always case-insensitive, and virtually every mail provider treats the local part as case-insensitive too. Keep the "Ignore letter case" option enabled unless you have a specific reason not to.
What counts as an invalid email address?
When the "Remove invalid email addresses" option is on, the tool drops entries that do not match the basic name@domain.tld shape, such as entries with missing @ signs, spaces or no domain extension. It is a format check, not a deliverability check, so a well-formed address that does not exist will still pass.
How many email addresses can I paste at once?
There is no hard limit. Because the processing happens locally in your browser, lists with tens of thousands of addresses are cleaned in well under a second on a typical computer.
What separators does the tool understand?
You can paste addresses separated by new lines, commas, semicolons, tabs or spaces, and you can mix separators freely. The output is always one address per line, which pastes cleanly into a Google Sheets column.
Now send them a personalized email
Paste your clean list into Google Sheets and send a personalized campaign with Mail Merge for Gmail.