Email Normalizer

Normalize email addresses by lowercasing, removing dots and plus aliases for Gmail, and trimming whitespace.

Email Normalizer tool

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Example

Input: John.Doe+newsletter@Gmail.com

Result: johndoe@gmail.com

Every address is trimmed and lowercased. For Gmail and Googlemail the dots in the local part and the +alias are removed, because Gmail delivers all of those variants to the same inbox; other providers are only lowercased.

How Addresses Are Normalized

InputNormalizedRules applied
John.Doe@Gmail.comjohndoe@gmail.comLowercase, Gmail dots removed
johndoe+news@gmail.comjohndoe@gmail.comGmail +tag removed
j.o.h.n.doe@googlemail.comjohndoe@gmail.comDots removed, domain set to gmail.com
Jane.Smith@Company.comjane.smith@company.comLowercase only
jane.smith+crm@outlook.comjane.smith+crm@outlook.comNone (not Gmail)
Bob@Yahoo.COMbob@yahoo.comLowercase only

Output of the normalizer for each input.

  1. Enter one or more email addresses, one per line.
  2. The rules apply as you type: lowercasing and trimming for every address, plus dot and +tag removal for Gmail.
  3. Compare each original address with its normalized version side by side.
  4. Check the highlighted rows and the Total, Modified and Duplicates counts to see what changed.
  5. Copy single addresses, the full list with "Copy All", or a de-duplicated list with "Copy Unique".

Cleaning Up Email Lists With Normalization

Email normalization turns different spellings of the same address into one standard form, so you can spot duplicates. This tool trims spaces and lowercases every address. For Gmail it also drops dots and +tags, so John.Doe+news@Gmail.com and johndoe@gmail.com both become johndoe@gmail.com.

Why only Gmail? Google states that dots in a Gmail username are ignored, and mail sent to name+anything@gmail.com still reaches name@gmail.com. The tool also maps googlemail.com to gmail.com, since both are the same service. Other providers follow their own rules. Some support +tags too, but on other mail servers a dot or plus sign can be part of a different mailbox. So for every other domain, the tool only trims and lowercases.

Paste one address per line. You get the original and normalized addresses side by side, with changed rows highlighted, plus counts for Total, Modified and Duplicates. Copy All keeps every row in order. When duplicates exist, Copy Unique keeps the first copy of each normalized address. Empty lines are skipped. The tool does not check whether an address is real or even well formed.

Use the normalized form for matching and deduping, for example to stop one person from claiming a sign-up offer twice with +tags. Keep the address the user typed as well, and send mail to that one. Lowercasing the part before the @ is safe with almost every real provider, even though the email standard allows case-sensitive mailboxes. For other list cleanup, the Remove Duplicate Lines and Case Converter tools can help.

Frequently Asked Questions

Yes. Gmail ignores dots in the username, so jane.doe@gmail.com, janedoe@gmail.com and j.a.n.e.doe@gmail.com all reach the same inbox, and the same goes for googlemail.com. This does not apply to Google Workspace addresses on a company domain or to most other providers, which is why the tool removes dots only for gmail.com and googlemail.com.
Anything between the + and the @ is a tag. Mail to jane+shop@gmail.com arrives at jane@gmail.com, and the tag lets you filter it or see which site shared your address. Gmail and several other providers support this. The tool strips tags only for Gmail, because on other servers a + can be part of a separate mailbox name.
In practice, no. The domain part is never case sensitive, and nearly all providers treat the part before the @ the same in any case. The email standard technically lets a server treat them differently, but that is very rare. Lowercasing the whole address, as this tool does, is the usual way to compare addresses.
The normalized form is good for spotting likely repeat sign-ups, such as free trial abuse. Be careful about blocking outright: some families share one inbox with tags, and rules differ outside Gmail. A common approach is to store both the original and the normalized address, and use the normalized one only for matching.
No. It normalizes whatever text you paste, even if it is not a working address. Run basic validation first, or scan the results for obvious errors. It also cannot tell whether a mailbox exists. Only a confirmation email that the user clicks can prove that.

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