Remove duplicate email addresses from a list with free starter credits
Duplicate entries appear when lists are combined, people sign up twice or CRM exports overlap. Email-address deduplication can reduce repeated sends and make a contact file easier to maintain.
Clean an email list with free credits →Three steps to deduplicate your email list
- Upload a CSV with the contact emails to the cleaner.
- Keep Remove duplicate addresses checked, then click Clean & verify; eligible domain checks use your account credits.
- Review the removed-rows CSV and download the cleaned output. The first occurrence of an address is retained.
What counts as a duplicate?
- The cleaner ignores letter case when comparing addresses: JOHN@example.com and john@example.com match.
- A different email address belonging to the same person is not automatically considered a duplicate.
- Gmail dot and plus aliases are not automatically merged in this build; removing those safely requires rules specific to the provider.
Combine duplicate removal with other rules
- You can also remove malformed email formats and optionally exclude known disposable or role-based email addresses.
- Suppression files subtract known bounced or unsubscribed addresses from the retained output.
- The original CSV remains unmodified on your computer; the cleaned result is a new download.
When duplicates are not the problem
- A clean-format address can still be an inactive or non-existent inbox.
- A duplicate-free list may still contain contacts who have opted out of marketing messages.
- Use the appropriate consent and suppression records regardless of the cleaning results.
Frequently asked questions
Does it remove duplicates in a 10,000-row list?
Yes, subject to the 20 MB and 250,000-row browser limits.
Will duplicate removal merge two different email addresses for the same person?
No. It compares email addresses, not people.
These tools improve list formatting and organisation. They do not guarantee delivery or replace permission to email your contacts.