Validate Email Address
Validate Email Address is a reusable JavaScript snippet. Validates email addresses using a comprehensive regex pattern. Also includes a simple domain check for MX records. The full implementation: function isValidEmail(email) { return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email) } // Strict validation (RFC 5322) function isValidEmailStrict(email) { return /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/.test(email) } // Validate email + domain async function isValidEmailWithDomain(email) { if (!isValidEmail(email)) return false const domain = email.split('@')[1] try { const res = await fetch(`https://dns.google/resolve?name=${domain}&type=MX`) const data = await res.json() return data.Answer && data.Answer.length > 0 } catch { return true } // Fallback to syntax check } // Usage isValidEmail('user@example.com') // true isValidEmail('not-an-email') // false This snippet uses only standard JavaScript with no dependencies, so it runs in modern browsers and Node.js alike. Browse more patterns in the snippet library, or paste the code straight into the playground to experiment with it.