Email Normalizer
Paste one email address per line or separated by commas, then get a clean list with predictable formatting and a review of entries that need attention.
A QUICK WALKTHROUGH
How to use this tool
- Paste up to 10,000 email entries separated by lines, commas, or semicolons.
- Choose whether to lowercase local parts and remove duplicate normalized addresses.
- Review valid and flagged entries, then copy or download the cleaned list.
Practical cleanup rules
The normalizer trims surrounding whitespace, treats line breaks, commas, and semicolons as separators, lowercases domains, optionally lowercases local parts, and removes exact duplicates after normalization. It checks only obvious practical syntax: one unquoted local part, one domain, no consecutive dots in the local part, and a domain with valid labels.
Review before sending
A syntactically valid address may still be inactive, mistyped, disposable, or unsuitable for your list. This browser-only tool never verifies that an address exists, queries DNS, contacts a mail server, or sends a message. Copy or download the result only after reviewing flagged entries and your consent requirements.
GOOD TO KNOW
Common questions
Does this verify that an email address exists?
No. It performs local syntax cleanup only. It does not query DNS, contact a mail server, or send a verification email.
How are duplicates removed?
After trimming and case normalization, the first occurrence is retained and later exact matches are omitted when Remove duplicates is enabled.
What happens to invalid entries?
They remain in a separate flagged list with a short reason so you can correct or discard them yourself.