← All posts

How to Send Morse Code with a Flashlight: Step-by-Step Guide

Sending Morse code with a flashlight is one of the most practical and oldest uses of Morse code. Whether you're signaling across a valley, communicating silently, or just having fun, all you need is a light source and knowledge of the code.

Basic Principles

Morse code with light uses the same dot-and-dash system as audio Morse:

  • Dot (dit): A short flash
  • Dash (dah): A long flash, about 3 times the length of a dot
  • Gaps: Pauses between flashes indicate character and word boundaries

Timing Guide

Pick a comfortable base speed and stay consistent:

ElementDurationExample at 1 sec/dot
Dot1 unit1 second
Dash3 units3 seconds
Element gap1 unit1 second off
Character gap3 units3 seconds off
Word gap7 units7 seconds off

For beginners, using 1 second per dot unit is a good starting pace. As you improve, you can speed up.

Step-by-Step: Sending a Message

Let's send "HELLO":

  1. H (....): Four short flashes, with brief pauses between each
  2. *Character gap*: Pause for 3 dot-lengths
  3. E (.): One short flash
  4. *Character gap*
  5. L (.-..): Short, long, short, short
  6. *Character gap*
  7. L (.-..): Short, long, short, short
  8. *Character gap*
  9. O (---): Three long flashes

Useful Messages to Know

MessageMorse CodeUse Case
SOS... --- ...Emergency distress
HI.... ..Greeting
OK--- -.-Acknowledgment
NO-. ---Negative
YES-.-- . ...Affirmative
HELP.... . .-.. .--.Request assistance

Tips for Clear Signaling

  1. Be consistent: Keep your dot and dash lengths steady
  2. Exaggerate the difference: Make dashes clearly 3x longer than dots
  3. Mind your gaps: The pause between characters should be noticeably longer than between elements
  4. Point your light directly: Aim at your receiver for maximum visibility
  5. Agree on speed first: If possible, establish a comfortable speed with your partner
  6. Use a smooth surface: Covering/uncovering the flashlight with your hand is smoother than toggling the switch

Using Your Phone as a Morse Flashlight

Modern phones make Morse code signaling easy. The Morse Code app lets you:

  • Type a message and your phone's flashlight transmits it automatically with perfect timing
  • Use presets for common messages like SOS
  • Adjust speed to match your recipient's comfort level
  • Choose screen flash if you don't have a flashlight (the screen pulses white)

The app handles all the timing math so your signals are perfectly formed every time.

Download free for iOS or Android.

Try the Morse Code App

Decode, transmit, and learn Morse code on your phone. Free for iOS and Android.