Normalize and sanitize email addresses to a canonical form for deduplication and data cleaning.
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About Email normalizer
Paste a list of email addresses, one per line, and get canonical forms for deduplication. Domains are always lowercased; optional steps lowercase the local part, remove +tags, remove dots from Gmail addresses, map googlemail.com to gmail.com, remove duplicates and drop invalid lines. It accepts mailto: prefixes and "Name <address>" forms and shows a per-line table of what changed.
Common uses
- Deduplicate a newsletter or CRM export where people signed up with user+tag@ variants.
- Detect repeated sign-ups that differ only in Gmail dots or letter case.
- Clean a pasted list of "Name <email>" entries into bare addresses.
- Flag malformed addresses before importing a list into another system.
FAQ
- Does Gmail ignore dots in email addresses?
- Yes. Gmail ignores dots in the username, so j.doe@gmail.com and jdoe@gmail.com reach the same inbox, and googlemail.com is an alias of gmail.com. This tool only removes dots for those two domains, because other providers may treat dots as significant.
- What is plus addressing (+tags)?
- Many providers, including Gmail and Outlook, deliver user+anything@domain to user@domain. Stripping the +tag reveals the underlying mailbox, but not every mail server supports it, so treat the result as a matching key rather than a guaranteed deliverable address.
- Are email addresses case-sensitive?
- The domain part is case-insensitive. The local part is technically case-sensitive under RFC 5321, but virtually all major providers treat it case-insensitively, which is why lowercasing is a common normalization step.