WhatsApp OTP vs SMS OTP: which should you use first?

Neither wins outright. Here's how to decide, and why cascading both beats picking one.

SMS is the default for a reason

It works on every handset, needs no app, and users expect it for verification. Its failure modes are network congestion, DND misrouting, and a full inbox on some handsets.

WhatsApp adds richer delivery confirmation

You get read receipts, not just delivery receipts, and a familiar interface for users who already live in the app. It fails when the user isn’t on WhatsApp, or hasn’t opened the app in a while.

The real answer: don’t choose, cascade

Send SMS first. If it doesn’t deliver in a set window, fall back to WhatsApp. If that isn’t read either, place an automated voice call. That’s exactly what MsgBridge Verify automates in one API call.