Using WhatsApp as a fallback for SMS OTP
If SMS is slow or fails, the same OTP is automatically delivered over WhatsApp — usually in under a second. You pay only for the channel that successfully delivers the code.
Most Indian smartphone users have WhatsApp, and WhatsApp OTPs arrive faster than SMS on an average day. Using WhatsApp as a first or fallback channel is the single biggest OTP-latency win for most apps.
How it works
- You send one /v2/otp/send request. We try your preferred channel first.
- If the primary channel doesn't deliver in your configured window (default 7s), we automatically send the same code over the fallback channel.
- The user sees whichever arrives first. The other is silently cancelled when the code verifies.
- You're only billed for the channel that actually delivered.
WhatsApp OTP is billed at the Authentication rate (₹0.1150 per conversation), usually cheaper than SMS in bulk.
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