Email Validator
Quickly check if an email address is valid. Validates email format and syntax in your browser and gives detailed feedback on common issues, including likely domain typos.
Email Address
Validation Results
Enter an email address to see validation results
Email Format Rules
Valid Characters
- •Letters (a-z, A-Z)
- •Numbers (0-9)
- •Special chars: . ! # $ % & ' * + / = ? ^ _ ` {|} ~ -
- •Plus sign (+) for aliases
Length Limits
- •Local part: max 64 chars
- •Domain part: max 253 chars
- •Total length: max 254 chars
- •Must contain exactly one @
Restrictions
- •No consecutive dots (..)
- •Can't start/end with dots
- •Can't start/end with hyphens
- •Valid TLD required (.com, .org, etc.)
Sample Emails
About Email Validator
A comprehensive email validation tool that checks email addresses for proper syntax, format compliance, and common structural issues. This tool applies practical, RFC-based syntax rules to confirm email addresses are formatted correctly. It checks syntax only; it does not check whether the address can receive mail.
Why use a Email Validator?
Invalid email addresses can cause delivery failures, bounce rates, and poor user experience in your applications. This validator helps prevent these issues by checking email syntax before processing, saving you from integration problems and ensuring your email lists maintain high quality and deliverability rates.
Who is it for?
Essential for web developers building contact forms, email marketers managing subscriber lists, data analysts cleaning email datasets, and anyone who needs to verify email address validity before storage or transmission. Perfect for both technical and non-technical users who work with email data.
How to use the tool
Enter the email address you want to validate in the input field
Click the validate button to check the email format and syntax
Review the detailed validation results and any specific error messages
Use the feedback to correct any formatting issues if needed
Copy or save valid email addresses for your applications or lists
Frequently Asked Questions
How do I validate an email address?
Paste an email address. The tool runs a syntax check based on RFC 5321/5322 (correct local-part + @ + domain structure, allowed characters, length limits) plus a check for likely typos in popular domains (for example gmial.com suggests gmail.com). The result tells you if the address is well-formed. Everything runs in your browser: the address is not sent anywhere, and the tool does not look up MX records, detect disposable domains, or connect to the receiving mail server.
What characters are valid in an email address?
RFC 5322 allows almost any printable character in the local-part (before the @): letters, digits, and !#$%&'*+-/=?^_`{|}~. Dots are allowed but cannot be consecutive or at the start/end. Quoted strings ('"hello world"@example.com') allow even more, including spaces, but this tool rejects them. Domain part follows RFC 1035 hostname rules: letters, digits, hyphens, dots (ASCII only; internationalized domains must be entered in punycode). Maximum total length is 254 characters. Many real-world mail servers reject technically-valid-but-unusual addresses, so 'syntactically valid' doesn't guarantee delivery. This tool errs on the side of being strict-but-practical, accepting what real mail systems accept.
Can I detect fake or disposable email addresses?
No. This tool checks syntax and likely domain typos only. It does not check whether a domain has MX records, whether it belongs to a disposable-email service, or whether the mailbox exists. To confirm that a user controls an address, use double opt-in: send a verification email and only activate the account after they click the link. To look up a domain's mail servers, use the [MX Lookup](/tools/mx-lookup/) tool.
Why are some valid emails being rejected as invalid?
This tool applies strict, practical rules: it rejects quoted local parts ("john doe"@example.com), comments, IP-literal domains, and non-ASCII characters, even though some of these are allowed by RFC 5322. A domain without a dot (user@localhost) is also rejected because it needs a top-level domain. If a user insists their address is valid, accept it with double opt-in: send a verification email and only activate the account after they click the link. Validation reduces friction; opt-in is the ground truth.
Should I check emails on the client or server?
Both. Client-side validation gives immediate feedback as the user types — improves UX, but can be bypassed (attackers can submit any string). Server-side validation is the authoritative check before storing or sending mail. Use the same validation rules in both places: the client-side check is a UX optimization, the server-side check is a security gate. This tool runs only in your browser and is meant for manual checks, not as an API. For high-volume signup forms, also rate-limit to prevent enumeration attacks where attackers iterate through emails to discover valid ones. See the [Email Deliverability 2026 Guide](/blog/email-deliverability-2026-spf-dkim-dmarc-bimi-warmup/) for end-to-end mailing best practices.
Why do some catch-all addresses pass validation but bounce?
Catch-all addresses (joe.smith@example.com when no 'joe.smith' user exists, but the domain accepts everything) look valid, and so does any well-formed address at a domain that doesn't exist. Validation can't distinguish without performing actual SMTP RCPT TO probing, which is intrusive and many servers refuse. The result: the address passes our check but bounces when you actually send mail. This is the gap between 'address is well-formed' (what this tool verifies) and 'address is a real, deliverable mailbox' (what only the receiving server knows). Double opt-in resolves this — the user must click a link sent to that address.
What's the difference between syntactic and deliverable validation?
Syntactic validation checks 'is this string formatted as an email per RFC 5322?' — fast, deterministic, no network calls. Deliverability validation checks 'will mail to this address actually reach the recipient?' — slow, probabilistic, requires DNS lookups (MX records) and ideally SMTP probing (which mail servers can refuse). This tool does only the syntactic check (plus domain typo suggestions). For deliverability ground truth, send a verification email and require the user to click a link.
How does this relate to the MX Lookup tool?
This tool doesn't query MX records; the [MX Lookup](/tools/mx-lookup/) tool does. Email Validator checks the address string in your browser, while MX Lookup shows which mail servers actually handle inbound mail for the domain (useful for delivery troubleshooting, provider identification, and infrastructure auditing). Use Email Validator to check how an address is written. Use MX Lookup when investigating a specific delivery problem ('why isn't my mail to support@vendor.com arriving?'). The [Email Deliverability 2026 Guide](/blog/email-deliverability-2026-spf-dkim-dmarc-bimi-warmup/) explains the full stack: MX, SPF, DKIM, DMARC, BIMI.
Share This Tool
Found this tool helpful? Share it with others who might benefit from it!
💡 Help others discover useful tools! Sharing helps us keep these tools free and accessible to everyone.