Test multi-channel OTP verification with your own API key. Send and verify OTPs via Email, SMS & WhatsApp instantly - no code required!
{
"channels": ["email"],
"recipients": {
"email": "your@email.com"
},
"sandbox_mode": true
}// API response will appear here after sending OTP...
// Try it now:
// 1. Enter your API key (or get one free)
// 2. Select channels (Email/SMS/WhatsApp)
// 3. Enter recipient details
// 4. Click "Send OTP"
// 5. Verify the OTP you receive!Simple 3-step process to test OTP verification
Enter your API key, select channels (Email/SMS/WhatsApp), and add recipient details. Enable sandbox mode for instant testing.
Click "Send OTP" to trigger the API call. OTP codes will be sent to your specified recipients instantly via selected channels.
Enter the OTP codes received and click "Verify OTP". See real-time verification results and response data.
Everything you need to test OTP API thoroughly
Test Email, SMS, and WhatsApp OTP in a single request. Select one or multiple channels simultaneously.
Get OTP codes directly in API response for testing. No need to wait for actual delivery during development.
See exact JSON payload being sent to API in real-time. Perfect for understanding request structure.
View complete API responses with syntax highlighting. Understand success and error responses instantly.
One-click copy for both request payload and response data. Speed up your development workflow.
Test complete OTP lifecycle from send to verify. Experience the entire authentication flow.
Perfect for developers and teams at every stage
Test OTP integration before writing code. Understand API behavior, response structure, and error handling.
Verify API endpoints and test error scenarios. Ensure your server-side implementation handles all cases.
Test OTP functionality end-to-end. Verify multi-channel delivery and validation logic thoroughly.
Experience OTP flow first-hand. Make informed decisions about user authentication experience.
Everything you need to know about testing OTP API
Yes, you need a Sendmator API key. You can sign up for free and get your API key instantly. Free credits are included!
Sandbox mode returns OTP codes directly in the API response instead of sending them via actual channels. Perfect for testing without consuming credits or waiting for delivery.
Yes! You can select Email, SMS, and WhatsApp simultaneously to test multi-channel OTP delivery in a single request.
While the tool is secure (uses HTTPS and doesn't store your data), we recommend using test API keys (sk_test_...) for testing. Your API key is only used for direct API calls and is never stored.
OTPs typically arrive within 10 seconds. Email is usually fastest (2-5 seconds), SMS takes 5-10 seconds, and WhatsApp 3-8 seconds depending on carrier networks.
This is a testing tool for developers. For production, integrate Sendmator OTP API into your application using our SDKs or REST API. See our documentation for integration guides.
Start building secure authentication in minutes. Free API key with included credits.
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