Email Address Validator

Check display-name mailbox syntax, local-part/domain structure, Unicode use, ASCII domain normalization, and byte-length warnings in the browser; no DNS, MX, SMTP, or delivery test is performed.

Runs locallySyntax ≠ deliverabilityIDN-awareDisplay names accepted

Email addressAllow internationalized local parts (SMTPUTF8 syntax mode)

ReadyNo network request is made.

—Local part

—Domain

—ASCII domain

—Address bytes

These tools work locally on text. Syntax validation is not mailbox verification: no DNS/MX lookup, SMTP connection, account-existence check, or deliverability test is performed.

Mailbox syntax, not mailbox existence

Accept bare addr-spec or display-name forms such as “Jane Doe <jane@example.com>”. Show entered IDN and normalized ASCII domain without pretending to perform DNS, MX, SMTP or inbox verification.

Deliverability remains a separate network question

These tools intentionally stop at local parsing, normalization and URI construction. A syntactically valid address can still have no MX service, no mailbox, a catch-all domain, or delivery restrictions; v266 does not label those network states without actually checking them.