...---...One continuous signal
This is the formal distress pattern used by the player. The last dot of the first S flows into the first dash of O with the same short inner gap used between all other signal elements.
Play · flash · copy · download
SOS in Morse Code: Pattern (...---...), Sound, Light and Meaning
SOS in Morse code is the universal distress prosign ...---...: three short signals, three long signals, and three short signals. Use the interactive transmitter to hear authentic CW audio beeps, watch flashlight blinking rhythms, explore exact millisecond timing, and download free emergency WAV audio.
SOS
...---...Three short · three long · three short9signal elements
23timing units
1.38 sat 20 WPM
5–40adjustable WPM
Interactive distress-signal practice
Play SOS in Morse Code: Audio, Light & Flash Signal
Hear and watch the continuous distress prosign: three short signals, three long signals, then three short signals.
Ready to play
SOS
...---...Light follows each active signalContinuous distress prosign
...---...Three dots · three dashes · three dots
S
S
S
O
O
O
S
S
S
- Dot length
- 60 ms
- Dash length
- 180 ms
- Prosign duration
- 1.38 s
- Spaced S O S
- 1.62 s
Vibration depends on browser and device support. This page is for learning and practice; in a real emergency, contact local emergency services whenever possible.
The pattern
The SOS Morse Code Pattern: Continuous Prosign vs Spaced Letters
The easiest way to remember SOS is three short, three long, three short. A short mark is a dot and lasts one timing unit. A long mark is a dash and lasts three timing units. A one-unit gap separates each of the nine marks in the continuous signal.
... --- ...S, O, and S with letter gaps
This readable form makes the three letters obvious, but it inserts normal three-unit gaps between S and O. At the same WPM it takes longer than the continuous prosign.
Same rhythm, different medium
How to Signal SOS in an Emergency (Sound, Flashlight and Finger Taps)
The medium can change, but the timing relationship stays the same. Keep every long signal about three times the duration of a short signal, use a brief pause between marks, and repeat the complete pattern only after a clear pause.
Step 01Memorize the Symmetrical Rhythm (...---...)Understand that SOS consists of three short dits (dots), three long dahs (dashes), and three short dits. In emergency signaling, transmit it continuously as one combined prosign without standard inter-letter pauses.
Step 02Transmit Using Audio Signals or WhistleProduce three short whistle blasts or audio beeps, three sustained blasts three times longer than the short ones, and three short blasts. Repeat the sequence every minute to guide searchers toward your location.
Step 03Signal Visually with Flashlight or MirrorAim your light source toward rescuers and flash three brief 1-second pulses, three sustained 3-second pulses, and three brief 1-second pulses. Pause 5 to 7 seconds between cycles so watchers can confirm the distress pattern.
Step 04Tap or Knock on Metal Pipes and StructuresIn collapsed structures or stranded vehicles, tap three quick knocks, three heavier/spaced knocks, and three quick knocks. Sound carries through solid metal and concrete much farther than human vocal shouts.
Learning tool, not an emergency service
This browser player demonstrates the Morse pattern and timing. In a real emergency, use available official emergency channels and contact local emergency services whenever possible.
A common misconception
What Does SOS Stand For in Morse Code? (History and Meaning)
SOS does not officially expand to “Save Our Souls” or “Save Our Ship.” Those phrases became useful memory aids after the signal was established. The sequence was valuable because its balanced rhythm is short, distinctive, and easy to recognize across languages and signaling methods.
Operators can write the sequence as the familiar letters S-O-S because three dots form S and three dashes form O in International Morse Code. The signal itself, however, is treated as one continuous procedural sequence rather than an ordinary three-letter word.
Exact duration
SOS Timing and Speed Breakdown (5–40 WPM Milliseconds)
Standard Morse timing defines a dot as one unit, a dash as three units, and each inner gap as one unit. The continuous SOS pattern contains 15 units of active signal and eight one-unit gaps, for a total of 23 units. Increasing WPM shortens every unit proportionally.
10 WPM2.76 sDot length: 120 ms. Useful for hearing the 3-3-3 structure slowly.
20 WPM1.38 sDot length: 60 ms. This is the default setting in the player.
30 WPM0.92 sDot length: 40 ms. The same pattern becomes much more compact.
Visual distress recognition
How to Tell When Morse Code Starts in Lights & Blinking Signals
When observing a flashing flashlight, distress beacon, or ship signal lamp at night, determining where the message begins is a vital survival and rescue skill. In continuous optical signaling, the cycle repeats indefinitely without verbal markers.
[ 5–7s DARK PAUSE ]1. Watch for the long resting gap
Transmitters always pause for 5 to 7 seconds of total darkness between cycles. This extended dark interval is your optical anchor; whatever follows immediately is the first element of the distress message.
● ● ● (Three 1s flashes)2. Identify three rapid flashes
The cycle always restarts with three brief, identical flashes (dots) separated by 1-second dark gaps. If you observe three sustained flashes (dashes) first, you caught the signal mid-transmission during the letter O.
Need to practice or transmit blinking light signals?
Use our interactive Morse Code Light Translator to turn your computer screen or smartphone camera strobe into an optical beacon with adjustable WPM flashing rhythms and instant SOS strobe mode.
Continue the task
Explore Related Morse Code Tools and Common Phrases
This page focuses on one continuous distress signal. Use the related tools to translate other messages, study every character, or decode an existing recording.
Morse Code Light TranslatorTransmit optical flashing signals, control flashlight strobes, and calibrate emergency visual SOS pulses.Flashlight Morse →Morse Code Sound GeneratorSynthesize authentic CW audio beeps from 400 Hz to 1000 Hz with Farnsworth timing and WAV download.Generate sound →Morse Code TranslatorOpen SOS as editable text, change playback settings, save audio, or replace it with a complete message.Open translator →Morse Code PracticeTrain your audio receiving ear with sound-first drills and adaptive repetition.Practice receiving →Morse Code QuizTest your letter, number, and word recognition in 10-question rounds.Take a test →Morse Code AlphabetLook up A–Z, numbers, and punctuation with individual playback, copying, and timing.Explore alphabet →Morse Code NumbersMaster numbers 0–9 symmetrical dot-dash patterns, timing rules, and digit drills.Study numbers →Morse Code Image TranslatorUpload photos, diagrams, or screenshots to automatically detect dots and dashes via OCR.Translate image →Morse Code ChartDownload high-resolution printable PDF chart with standard alphabet, numbers, and distress signals.Download chart →How to Learn Morse CodeMaster sound recognition and 15–20 WPM copying speed using the Koch method and Farnsworth timing.Learn Morse →Help in Morse CodeSignal Help and Help Me using CW tone beeps, structural pipe tapping rhythms, and survival flashing.Learn help signal →Morse Code Audio Decoder & ListenerListen to Morse beeps via microphone or upload an audio file when the message already exists as recorded sound.Listen & decode →I Love You in Morse CodeCopy, hear, flash, and download a complete three-word phrase with letter-by-letter playback.Play the phrase →Hello in Morse CodeLearn how to tap, blink, hear, and transcribe the most popular beginner greeting in Morse code.Say hello →
FAQ from real search questions
Frequently Asked Questions About SOS in Morse Code
Answers about the continuous pattern, sound, light, timing, meaning, and downloadable audio.
What is SOS in Morse code?
SOS in Morse code is the universal distress signal transmitted as three short dots, three long dashes, and three short dots (...---...). Officially adopted in 1908, it is transmitted as one continuous prosign without inter-letter spaces, ensuring maximum acoustic clarity across noisy emergency radio channels.
How do you write SOS in Morse code (...---... vs ... --- ...)?
SOS in Morse code is officially written as a continuous unspaced prosign ...---... (often marked with an overbar as SOS). While educational charts write '... --- ...' with three-unit letter spaces to show individual S and O characters, real emergency transmissions omit letter pauses for continuous speed.
What does SOS sound like in Morse code?
SOS in Morse code sounds like three rapid dits, three long dahs, and three rapid dits (di-di-dit dah-dah-dah di-di-dit). The dashes last exactly three times longer than the dots, creating an unmistakable symmetrical rhythm that stands out distinctly against background noise or static.
How to tell when Morse code starts in lights or visual signals?
To tell when Morse code starts in lights, look for the prolonged dark resting pause of 5 to 7 seconds between transmission cycles, followed immediately by three rapid, 1-second short flashes (dots). Because emergency SOS is sent as an unbroken loop, recognizing the long pause prevents observers from mistaking the middle dashes (O) for the start of the message.
How do you flash or blink SOS with a flashlight in an emergency?
To flash SOS with a flashlight, send 3 quick flashes (1 second each), 3 sustained flashes (3 seconds each), and 3 quick flashes. Leave a brief 1-second pause between flashes, followed by a longer 5 to 7-second pause before repeating the entire cycle toward search and rescue teams.
How to blink SOS in Morse code using eyes or a light switch?
To blink SOS with your eyes or a light switch, close your eyes for 3 brief half-second blinks, followed by 3 deliberate prolonged closures held three times as long, and conclude with 3 brief blinks. Keep a distinct resting interval before repeating so observers can confirm intentional distress communication.
How to tap or knock SOS in Morse code with fingers or a tool?
To tap SOS in Morse code, knock 3 quick taps, pause briefly, knock 3 heavier or slightly slower taps, and finish with 3 quick taps. When trapped in rubble or stranded in a vehicle, tapping on metal pipes or car frames resonates far farther than shouting.
Does SOS officially stand for Save Our Souls or Save Our Ship?
No, SOS does not stand for 'Save Our Souls' or 'Save Our Ship' in official maritime regulations. The letters S-O-S were chosen purely because three dots, three dashes, and three dots formed the most recognizable, rhythmically distinct sequence that could not be easily misread under stressful radio conditions.
What is the difference between SOS and older distress codes like CQD?
SOS replaced CQD ('Come Quick, Danger') in 1908 because CQD (-.-. --.- -..) was longer, more complex, and frequently confused with routine callouts. The simple symmetry of ...---... proved significantly easier for ship operators to send rapidly and detect through heavy atmospheric static.
What is the exact timing and duration of an SOS transmission?
A standard continuous SOS pattern contains 23 timing units: 9 marks (6 dots of 1 unit plus 3 dashes of 3 units = 15 units) plus 8 one-unit internal gaps. At a standard 20 WPM rate (60 ms per unit), a single complete SOS signal takes exactly 1.38 seconds to transmit.
Can I download free emergency SOS Morse code sound audio (WAV)?
Yes, you can download authentic emergency SOS Morse code audio in WAV format directly from our interactive transmitter above. Choose your preferred speed from 5 to 40 WPM, test playback at 600 Hz standard pitch, and click 'Download WAV' for offline emergency preparedness training.
Why is Morse code SOS still taught and used in modern survival?
Morse code SOS remains a vital survival skill because it requires zero electronic cellular network or language fluency to communicate distress. Anyone can signal SOS using simple tools like flashlights, whistles, car horns, mirrors, or rock taps to attract airborne and ground rescuers.