Push Notification vs SMS Notification: What's the Difference?

SMS notifications are text messages sent to a phone number, reaching essentially anyone with a mobile phone regardless of whether they have a specific app installed - they land directly in the phone's inbox and stay there until the recipient deletes them.

Push notifications are alerts sent through an app, requiring the recipient to have that app installed and to have opted in to receive them - delivered almost instantly, but capable of disappearing from a lock screen if the recipient doesn't act on them right away.

The choice between the two comes down to reach versus cost and urgency versus engagement. SMS reaches a far broader audience since it needs no app installation, and with the large majority of text messages read within minutes of arriving, it's the more reliable channel for anything time-sensitive or high-priority - appointment reminders, delivery updates, two-factor codes, fraud alerts. Push notifications can't match that guaranteed reach, since they depend entirely on app adoption and opt-in, but they're effectively free to send at volume and deliver just as fast, which makes them well suited to ongoing engagement and marketing nudges - offers, feature announcements, re-engagement prompts - where occasionally being missed or dismissed isn't a serious problem. Most mobile-first businesses run both together rather than choosing one, using SMS for messages that genuinely need to land and push for the higher-volume, lower-stakes engagement work SMS would be too costly and intrusive to handle at the same scale.