Should I use SMS or push notifications for critical alerts?

For critical alerts, use SMS only if you need the highest likelihood the message is seen quickly and you can’t assume the user has your app open or push enabled. In many cases, the best answer is both, with a fallback strategy.

Quick rule of thumb

• Use push notifications if:
  • Users have your app installed and notifications enabled
  • The alert is important but not truly life/safety critical
  • You want lower cost and richer messaging
• Use SMS if:
  • The alert is urgent and must reach the user even if they’re not using your app
  • You need maximum reach across device states and notification settings
  • The message must arrive even when push may be disabled or delayed

Best practice for critical alerts

For genuinely critical events:

1. Send push immediately
2. Also send SMS as backup if no acknowledgement within a short window
3. Escalate to phone call or other channel if still unacknowledged

Tradeoffs

SMS

• Pros: Very high reach, no app required, usually seen quickly
• Cons: Costs more, shorter messages, less contextual, can be missed in notification overload

Push

• Pros: Cheap, rich content, better user experience, easy to target
• Cons: Requires app install and permissions, can be disabled, may be delayed by OS/device settings

Recommendation

If the alert is business-critical or safety-critical, don’t choose one channel—use a multi-channel escalation flow.
If you must choose one, SMS is usually better for critical alerts, while push is better for important but non-emergency alerts.

If you want, I can help you design a decision matrix for your specific use case.