Email Normalizer

The Email Normalizer cleans up a list of email addresses by reducing each one to its canonical form. It is built for the messy reality of exported contact lists, signup dumps and CRM exports, where the same person shows up as John.Doe@gmail.com, johndoe+news@gmail.com and j.o.h.n.d.o.e@googlemail.com — three spellings of a single mailbox. Normalizing first, then de-duplicating, turns those into one address so your counts, mail-merges and suppression lists are accurate.

Everything runs in your browser. Paste your addresses, toggle the rules you want, and the normalized list appears instantly.

How to use it

1. Paste one email address per line into the input box.
2. Choose which normalization rules to apply with the checkboxes.
3. Copy or download the cleaned list from the output box.

The four rules are independent, so you can mix and match:

• Remove dots from local part (Gmail-style) — Gmail and Google Workspace ignore dots before the @, so john.doe@gmail.com and johndoe@gmail.com reach the same inbox. This only applies to gmail.com and googlemail.com; dots are left alone for every other provider, where they are significant.
• Remove plus (+) aliases — strips sub-addressing tags, turning user+newsletter@example.com into user@example.com. This works for any provider that supports plus addressing.
• Convert to lowercase — lowercases the whole address so Jane.Smith@Example.com and jane.smith@example.com match.
• Remove duplicate emails after normalization — collapses addresses that become identical once the rules above are applied, keeping the first occurrence.

The tool also maps the googlemail.com domain to gmail.com, since they are the same Google service.

Why do the same inbox's addresses differ?

Providers apply their own rules to the local part (the bit before the @). Gmail ignores dots and everything after a +. Case is generally ignored by mail servers for the domain, and by most for the local part. Normalizing applies these rules up front so two spellings of one mailbox are recognized as one.

Does it validate that an address exists?

No. This tool normalizes formatting only. It does not send mail, check MX records or verify that a mailbox is deliverable. A line without an @, or with an empty local part or domain, is dropped from the output.

Will it change addresses at non-Gmail providers?

Dot removal is deliberately limited to Gmail and Google Workspace. For other providers, dots and case in the local part can be meaningful, so the tool only lowercases and strips plus-aliases there — it never removes dots outside the Gmail family.

Can I process a whole file?

Yes. Switch to Batch mode to run the same rules across multiple uploaded text files at once and download the results together.

Privacy

Email addresses are personal data, and this tool treats them that way. All normalization happens locally in your browser using JavaScript — nothing is uploaded to a server, logged or stored. Shareable links carry your chosen options but never the addresses themselves.