# SOS signal with your phone's screen and torch

> Flash SOS in Morse code with your phone's screen or torch and sound a loud whistle tone, free and offline, if you are trapped or need to be found in an emergency.

- Canonical URL: https://emergencyradio.co.uk/sos-signal/
- Source: [UK government, Be Ready: be ready for emergencies](https://beready.campaign.gov.uk/be-ready-for-emergencies/)
- Checked: 2026-10-25

This page includes a free interactive tool that runs in the browser and sends no data. The figures and rules it uses are the ones stated on this page, with their sources.

## When to use it

If you are trapped, injured or cut off and rescuers may be nearby, a visible and audible signal helps them find you. Always call 999 first if you have any signal.

## What it does

- **Screen:** flashes SOS in Morse code (three short, three long, three short) across the whole screen and keeps the screen awake.
- **Torch:** flashes the same pattern with your phone's torch on Android phones using Chrome; the phone asks for camera permission, because that is how a web page reaches the torch. Nothing is recorded.
- **Whistle tone:** a loud, high tone in the same rhythm. Keep the phone away from your ear.

The flashing stays under three flashes a second. If flashing lights affect you or someone nearby, use the sound only.

## Without internet

Open this page once and add it to your home screen: it then works offline, like an app.

## Save your battery

Signalling uses a lot of power. Signal in bursts when you hear or see rescuers, and keep the rest of the battery for calls and texts. A real whistle and torch in your emergency kit do the same job without draining the phone.

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Emergency Radio UK · Contact: contact@emergencyradio.co.uk