Email Syntax Validator — Check Email Addresses Free Online
Validate email addresses for correct syntax. Batch-check multiple addresses at once — paste one per line. Checks local part, domain, TLD, and length limits. Runs locally, no data sent anywhere.
Last updated:
CommentsPaste email addresses one per line to check syntax — validates local part, domain, TLD, and total length (RFC 5321/5322 limits).
What is Email Validator?
Email syntax validation checks addresses against the grammar defined in RFC 5322. It verifies: the presence of exactly one @ symbol, a non-empty local part (before @), a domain with at least one dot, no spaces, and total length ≤ 254 characters. It does NOT send mail or check if the mailbox exists — it validates the structural grammar of the address.
How to validate an email address
- 1Paste one or more addresses, one per line.
- 2Each line shows a green ✓ (valid syntax) or red ✗ (invalid) with the reason.
- 3Fix invalid addresses and re-check.
Frequently Asked Questions
Does this check if the email actually exists?
No — this is a syntax validator. It checks that the address follows RFC 5322 syntax, but does not send mail or verify the mailbox exists. Syntax validation catches typos, missing @ signs, and malformed domains.
What's the maximum length of an email address?
254 characters per RFC 5321. The local part (before @) is max 64 characters. Our validator checks both limits.
Can I validate a list of emails at once?
Yes — paste multiple addresses one per line. The tool validates each line independently and shows pass/fail results.
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