Cell Broadcast: how your phone receives emergency alerts

Cell Broadcast is a mobile network technology that sends a short message to all phones within range of certain towers at the same time. It is used for emergency alerts: danger warnings, severe weather and evacuations.

Cell Broadcast is like a loudspeaker in a square

In plain words

A text message is like a letter the postman delivers to each flat separately: with a million letters, the queue takes hours. Cell Broadcast is like an announcement over a loudspeaker in a square: everyone nearby hears the same message at once, and there is no queue.

How it works

Emergency services create a message for a specific area.
The operator broadcasts it through the towers in that area.
Every phone connected to those towers receives it at the same time.
No phone number or internet is needed, and the network does not get overloaded.
The phone shows the message on top of all apps, often with a loud alarm.

An emergency alert on top of all apps

Where you'll see it

In phone settings: "Emergency alerts" or "Wireless emergency alerts". In the EU these systems are called EU-Alert and operate in many countries. Availability in a given country depends on government services and operators.

Does it matter when buying

Yes, it is about safety. I recommend checking your emergency alert settings and leaving them on. But do not rely on them alone: also install the official alert apps for your area and follow your local authorities' official channels.

Myths

Myth: Alerts arrive as ordinary text messages. Reality: No, it is a separate broadcast technology not tied to your number.
Myth: Without internet, the alert will not arrive. Reality: Cell Broadcast works over the mobile network without mobile data.

FAQ

How do I turn on emergency alerts?

Settings - Safety and emergency (or Notifications) - Wireless emergency alerts.

Will I get alerts in airplane mode?

No, the phone must be connected to the mobile network.

Can I turn off the loud alarm?

Some categories can be turned off, but the most important alerts usually cannot.