Glint
By light
Three short flashes, three long, three short. A long flash is three times a short one. Pause, then repeat.
Emergency signal
SOS in Morse code
Three dots, three dashes, three dots. Press the light to hear the timing.
S···O−−−S···
To send it as light, use Glint.
It drives the iPhone's flashlight.
In an emergency, phone first if you can: 911 in the US and Canada, 999 in the UK, 112 across the EU. Signal when you cannot call, or to help rescuers find you.
By sound
The same pattern on a whistle or a horn: three short blasts, three long, three short.
By tapping
Three quick taps, three slow, three quick. Slow means a longer pause after each tap.
In the app
SOS from the Home Screen
Press and hold the Glint icon and choose Send SOS signal. Glint sends the call with the flashlight or the screen, at the correct timing.
This page only plays the sound. Glint sends it as light, and it works with no signal.
Why three dots and three dashes
SOS is not an abbreviation. It was adopted because the pattern is simple to send and hard to mistake, even through noise. It is sent as one unbroken run, without the pause that normally separates letters.
Questions
What is SOS in Morse code?
Three dots, three dashes, three dots: · · · − − − · · ·. As a distress call it is sent as one unbroken run, without the usual pause between letters, then repeated after a gap.
How do I send SOS with a flashlight?
Three short flashes, three long flashes, three short flashes. Make each long flash three times as long as a short one. Pause, then repeat. Glint's Send SOS shortcut does the timing for you with the iPhone's flashlight.
Does SOS stand for anything?
No. It was chosen because the pattern is simple to send and hard to mistake. Save our souls and save our ship came later.
How do I tap SOS?
Three quick taps, three slow taps, three quick taps. Because a tap cannot be held, slow means a longer pause after each tap.
Learn Morse in 13 hours
Glint is free on the App Store, for iPhone.