What this validator does
We validate at three levels:
- Basic syntax. An at-sign, a domain with a dot, no spaces, no forbidden characters.
- Domain structure. The TLD must be at least two characters and not end in a dot.
- Typo detection. If you typed
gmial.com,hotmial.com,outlok.comor other frequent mistakes, we suggest the fix.
What we don't do
We don't verify whether the mailbox exists. That requires SMTP connections to each provider, IP reputation maintenance, and paid services like ZeroBounce, NeverBounce or Kickbox. For bulk existence verification, use those. For fast syntax and typo cleanup, this tool is enough — and free.
Why validation matters
- Bounce rate. Mailchimp, SendGrid, Klaviyo and any ESP punish your reputation if more than 2% of sends bounce. A poorly-validated list can freeze your account.
- Cost. Many CRMs charge per active contact; every invalid email is wasted spend.
- Conversion. If a user signs up with a typo and never receives the confirmation, they're lost.
- Support. Tickets that arrive with an invalid email in the form are impossible to resolve.
How to handle results
After validation we show three categories:
- Valid — pass syntax and have no detectable typos.
- With suggestion — syntax OK but the domain looks suspiciously close to a popular one. We show the fix.
- Invalid — broken syntax; discard or ask the user to re-enter.
Limits of syntax-only validation
An email can be syntactically perfect and still not exist. Examples:
x@gmail.com passes every rule but probably has no account.
fakeemail123@gmail.com too. For high-stakes cases (B2B, big purchases),
combine this filter with an SMTP service: this kills 70-80% of issues, the SMTP gets
the rest.
Privacy
The emails you paste are processed in your browser. We don't send them to any server, store them or log them. Safe for customer lists — the code runs 100% local.