Email normalizer
What is an Email Normalizer?
The same mailbox can be written in many ways. [email protected], [email protected] and [email protected] all deliver to the same Gmail inbox. When you deduplicate a mailing list, detect repeated free-trial signups or match customer records, comparing raw strings misses these duplicates. This normalizer converts addresses to a canonical form for comparison.
How to use it
- Paste one or many email addresses, one per line.
- Choose the normalization rules to apply.
- Copy the normalized list, or use it to find duplicates.
Normalization rules
- Trim and lowercase: remove whitespace and lowercase the domain. The local part is technically case-sensitive, but virtually every provider treats it as case-insensitive.
- Remove plus addressing:
name+tag@domainbecomesname@domainfor providers that support sub-addressing, such as Gmail, Outlook and Fastmail. - Remove dots for Gmail: Gmail ignores dots in the local part.
- Domain aliases:
googlemail.comis equivalent togmail.com.
Example
[email protected] normalizes to [email protected].
Use normalized emails carefully
- Store the original address for sending; use the normalized version only as a lookup key.
- Dot removal must only be applied to Gmail. For most other providers,
j.doeandjdoeare different people. - Some users rely on plus tags to filter mail, so do not rewrite the address they gave you.
Frequently Asked Questions
Why normalize email addresses?
To detect duplicates and match records, because the same inbox can be written in many different ways.
Does Gmail really ignore dots?
Yes. Gmail ignores dots in the part before the @, so john.smith and johnsmith reach the same inbox.
Should I send email to the normalized address?
No. Keep and use the original address. Use the normalized form only for comparisons.
What is plus addressing?
Adding +tag before the @, as in [email protected]. Supporting providers deliver it to the main mailbox.
Can normalization detect all duplicate accounts?
No. It catches common variations such as case, dots and plus tags, but people can still use completely different addresses or disposable email services.