Email address validator
This email address validator checks whether each address in a list is written correctly. Marketers cleaning a mailing list and developers testing form validation use it to find typos such as double dots, missing domains or stray spaces.
- Runs in your browser
- Free, no account needed
- Copy or download the result
Result
Example
[email protected] [email protected] [email protected] admin@localhost "john smith"@example.org
Valid: 2 of 5 Result Address Reason Valid [email protected] Invalid [email protected] Local part has two dots in a row. Valid [email protected] Invalid admin@localhost Domain has no top-level domain, such as .com. Invalid "john smith"@example.org Quoted local part. RFC 5322 allows it, but many services reject it. Choose Allow quoted local parts to accept it. This checks syntax only. It cannot tell whether the domain accepts mail or the mailbox exists; only sending a message can confirm that.
How to use the email address validator
- Paste one address per line into the One email address per line box.
- Choose whether to accept Quoted local parts.
- Press Run to see Valid or Invalid with a reason for each line.
- Use Copy result or Download to keep the results.
How it works
The part before @ may be up to 64 characters and the whole address up to 254.
Unquoted local parts may use letters, digits and the symbols RFC 5322 allows, with no leading, trailing or double dots.
The domain needs at least two labels of letters, digits and hyphens, each up to 63 characters and not starting or ending with a hyphen, and a top-level domain that is not all digits.
IP address literals and non-ASCII addresses are marked invalid with a note, and quoted local parts are rejected unless you allow them.
This is a syntax check only. It cannot tell whether the mailbox exists or accepts mail.
Everything runs in your browser. Your input is not uploaded or stored.
Questions and answers
Can this tell if an email address is real?
No. It only checks that the address is written correctly. Only sending a message, or a check against the mail server, can show whether the mailbox exists.
What is the maximum length of an email address?
In practice the part before @ can be 64 characters and the full address 254 characters.
Are plus signs allowed in email addresses?
Yes. A plus sign is valid in the local part, as in [email protected], and many providers use it for sub-addresses.