๐ง Email Validator
Check on the spot whether an entered email address is correctly formatted, and see it split into its local part (before the @) and domain part (after the @). Useful for testing form input or spotting typos in an email address. Everything runs in your browser; nothing is sent anywhere.
How to use
- Enter the email address you want to check.
- Whether it's correctly formatted, plus its local and domain parts, are shown automatically.
How the calculation works
An email address has the form local-part@domain. This tool checks the format with essentially the same rule the HTML specification (WHATWG) uses to validate input type="email" in browsers. The local part may contain letters, digits and the symbols . ! # $ % & ' * + / = ? ^ _ ` { | } ~ -. The domain is a series of dot-separated labels, each starting and ending with a letter or digit, with hyphens allowed in between and a maximum of 63 characters. This tool also requires at least one dot in the domain (a form like example.com). The full email specification (RFC 5322) is more permissive still, allowing quoted local parts and more, but in practice most services accept only a stricter form like this one.
Worked example
taro.yamada+news@example.co.jp โ valid (local part taro.yamada+news, domain example.co.jp) user@localhost โ invalid (no dot in the domain) user@-example.com โ invalid (label starts with a hyphen) user name@example.com โ invalid (contains a space) The "+news" part is a subaddress; with Gmail and many other services, mail to it arrives in the same inbox as user@example.com.
Things to be aware of
- This checks format only; it cannot tell you whether the address exists or will receive mail.
- Internationalised addresses containing non-ASCII characters are not supported.
- Consecutive dots ("..") are invalid by the specification but may not be flagged by this tool.
- Some services reject addresses that pass this check.
FAQ
Can this tell me whether the email address actually exists?
No โ this tool only checks whether the string is correctly formatted. It cannot confirm whether mail sent to that address would actually be delivered.
Does this support internationalized email addresses?
No โ this tool is designed for standard ASCII-format email addresses using common letters, numbers, and symbols.
Is the email address I enter sent to a server?
No. All validation happens entirely in your browser's JavaScript; nothing is ever sent anywhere.