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Email Address Validator

Validate email syntax, inspect local parts and domains, and check multiple addresses at once.

Email address

Enter an email address to validate

Type or paste an email above to check its syntax, local part, and domain format.

All validation runs locally in your browser. Email addresses are never sent to any server.

What Is Email Validation?

Email validation is the process of verifying that an email address conforms to the syntax rules defined in RFC 5321 and RFC 5322. A valid email consists of a local part (before the @), an @ symbol, and a domain (after the @). This tool checks format compliance — it does not connect to mail servers to verify whether the address actually exists or can receive mail. For server-level verification, you would need an SMTP check or email verification API. Client-side syntax validation is the essential first step in any email workflow, catching typos and formatting errors before they cause delivery failures.

Email Syntax Rules

ComponentRule
Total lengthMaximum 254 characters
Local partMax 64 characters. Allowed: a-z A-Z 0-9 . ! # $ % & ' * + / = ? ^ _ { | } ~ -
DomainMax 253 characters. Must contain at least one dot. TLD must be at least 2 characters.
No consecutive dotsNeither local part nor domain may contain ..
No leading/trailing dotsLocal part and domain cannot start or end with a dot

How to Use the Validator

  1. Choose a mode — toggle between Single (real-time validation as you type) and Batch (validate multiple addresses at once).
  2. Enter email(s) — type or paste the address(es). In batch mode, separate entries with commas, semicolons, or new lines.
  3. Review results — single mode shows a detailed breakdown. Batch mode shows a table with status, parts, and errors for each address.

Limitations

  • Syntax Only

    This tool checks format compliance, not mailbox existence. A valid syntax does not guarantee the address can receive mail.

  • No SMTP Check

    No connection is made to the mail server. Server-level verification requires MX record lookups or SMTP handshakes.

  • International (IDN) Emails

    This validator uses basic ASCII rules. Internationalized email addresses with Unicode characters may not be fully covered.

  • Disposable Emails

    Temporary or disposable email addresses (e.g., mailinator.com) pass syntax validation but are not detected by this tool.

Frequently Asked Questions

Does a valid result mean the email exists?
No. Syntax validation confirms the email follows RFC format rules. To check if a mailbox actually exists, you would need an SMTP verification service or MX record lookup. Many email addresses with perfect syntax may still bounce because the mailbox does not exist, the domain does not accept mail, or the mailbox is full.
What is the maximum email length?
RFC 5321 specifies a maximum total length of 254 characters. The local part is limited to 64 characters and the domain to 253 characters. Most email providers impose even stricter limits in practice.
What characters are allowed in the local part?
The local part (before @) may contain: uppercase and lowercase letters (A-Z, a-z), digits (0-9), and the special characters . ! # $ % & ' * + / = ? ^ _ { | } ~ -. Dots cannot appear consecutively, at the beginning, or at the end of the local part.
Can I validate a list of emails at once?
Yes — switch to Batch mode and paste or type multiple addresses separated by commas, semicolons, or new lines. The tool will validate every address and display a table with status, local part, domain, and any errors found.
What is the difference between syntax and MX validation?
Syntax validation checks the string format (local part, @, domain structure). MX validation checks whether the domain has mail exchange (MX) records in DNS, indicating it can receive email. A domain may pass syntax check but have no MX records, meaning mail would bounce. This tool provides syntax validation only.

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