Cloudmersive Validate API

⭐ Beginner's Pick Email / API Key Intermediate HTTPS CORS
Varies by plan (check documentation)

Overview

Cloudmersive Validate is a comprehensive validation API that can verify email addresses, phone numbers, VAT numbers, and domain names in a single platform. It combines syntax checks with live DNS and SMTP lookups for accurate real-world validation. A good choice when you need multi-type validation without integrating separate APIs.

💡

Beginner Tip

The free tier gives you 800 API calls per month across all Cloudmersive APIs — start with email validation as it is the most commonly needed feature. Use the /validate/email/address/full endpoint for the most complete check, including disposable detection and SMTP verification.

Available Data

email delivery status
message ID
bounce/complaint data
open/click tracking
phone number validation
carrier information

Example Response

JSON Response
{
  "message_id": "msg_abc123def456",
  "status": "delivered",
  "to": "[email protected]",
  "subject": "Welcome!",
  "timestamp": "2025-01-15T10:30:00Z"
}

Field Reference

ValidAddress Overall validation result — true if the address is valid and deliverable
UserName The local part of the email address (before the @)
Domain The domain portion of the email address
IsDisposable Whether the address uses a known disposable email service
IsFreeEmailProvider Whether the domain belongs to a free email provider like Gmail or Yahoo
SmtpServerResponse Raw SMTP server response message from the deliverability check

Implementation Example

const url = "https://cloudmersive.com/validate-api";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
  headers: {
  "X-API-Key": "YOUR_API_KEY"
  }
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

401 Unauthorized Missing or invalid Apikey header
Add the header Apikey: YOUR_API_KEY — the header name is "Apikey" with a capital A, not "Authorization"
403 Forbidden Monthly API quota has been exhausted
Check your usage in the Cloudmersive dashboard and upgrade your plan if needed
Slow response time Full email validation performs live SMTP checks which can take 2-5 seconds
Use /validate/email/address/syntaxOnly for fast syntax-only checks when speed matters more than full accuracy

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 15/20
🔒 Security 15/15
🛠 Developer XP 17/20
✓ Reliability 10/15

Partially tested on Apr 5, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS YES
Category Email
Difficulty Intermediate
Verified: 2026-04-04

Similar APIs

View All →