Signal Rain: Morse code typing game
A Morse code typing game: letters fall, and you key each one in Morse before it lands, or name the Morse as it falls. One key or two, on a phone or a keyboard.
- Score
- 0
- Wave
- 1
- Streak
- 0
- Lives
- Best
- 0
See mode
- Characters fall as dots and dashes. Type each one before it lands.
- Five catches in a row double the points.
- 1Pick a modeKey the letter, or name Morse you see or hear
- 2Choose one key or twoIn Key mode, tap one pad or use two
- 3Pick a level and startEasy, Normal or Hard, then press Start
How to use
- Pick a mode: Key (you see a letter and key its Morse), See (you see Morse and type the letter) or Hear (you hear Morse and type the letter).
- In Key mode, pick One key (tap the pad, Space or Ctrl: short for a dot, long for a dash) or Two keys (a dot key and a dash key, then Send).
- Choose Easy, Normal or Hard and press Start.
- Deal with the lowest letter first. A right answer catches it; catching it high up scores more, and five in a row double the points.
- Three letters that land end the game. The recap lists them with their codes; press one to hear it.
What it does
Signal Rain is a Morse code typing game for both directions of typing.
- Key mode. Each drop shows a letter; you type its Morse code. A sidetone sounds as you key.
- One key that learns your timing. Tap for a dot, hold for a dash. After a few of each, the dash point moves to fit your rhythm.
- Two keys. Dot on “.” or J, dash on “-” or K, as on Gboard's Morse keyboard; nothing depends on timing.
- See and Hear modes. Read the dots and dashes, or hear them with the drop hidden, and type the letter. Pick the Morse speed you hear and the tone's pitch.
- Show codes. In Key mode, each drop can show its dots and dashes while you learn.
- Waves and streaks. Each wave is longer and faster; five catches in a row double the points, ten triple them.
- A recap that teaches. The letters that landed, with their codes and sound.
How it works
Morse timing follows ITU-R M.1677-1: a dot is one unit, a dash three, the gap inside a letter one unit, between letters three and between words seven.
With One key, only the length of each press tells a dot from a dash. The game starts with the dash point at 300 ms, about 8 words per minute: a shorter press is a dot, a longer one a dash.
After your last 12 presses hold at least two short and two long ones (at least 1.8 times as long), the dash point moves to the middle of your own dots and dashes, between 80 and 900 ms. A letter is sent when you pause for 2.5 times the dash point (750 ms at the start, never under 350 or over 900 ms), or at once with Enter.
With Two keys, every mark is exact, and the letter is sent when you press Send, Space or Enter.
The sent code catches the lowest falling letter with that code. While you key, the code turns red as soon as no falling letter starts with it, so you can press Back early.
| Level | Letters | First wave falls in about | Key mode |
|---|---|---|---|
| Easy | K M U R E S N A P T (the first 10 Koch letters) | 10 s | 13.5 s |
| Normal | A to Z | 8 s | 10.5 s |
| Hard | A to Z and 0 to 9 | 6 s | 8 s |
Each wave has two more drops than the last. Its drops fall faster, by 12% of the first wave's speed each time, and come 10% closer together (never under 0.6 s apart). In Key mode drops fall at three quarters of the speed and arrive a third further apart, because keying a letter takes longer than naming it.
Examples
How to key some letters:
| Letter | Morse code | One key | Two keys |
|---|---|---|---|
| A | .- | tap, hold | J K, Send |
| B | -... | hold, tap, tap, tap | K J J J, Send |
| C | -.-. | hold, tap, hold, tap | K J K J, Send |
| E | . | tap | J, Send |
| S | ... | tap, tap, tap | J J J, Send |
| O | --- | hold, hold, hold | K K K, Send |
E is the shortest code of all, a single dot. For every other character, see the Morse code alphabet.
Good questions
Frequently asked questions.
About Signal Rain
How do you type Morse code on a keyboard?
Use two keys or one. With two keys, press a dot key and a dash key (here “.” or J and “-” or K) and then Space to finish the letter. With one key, hold Space or Ctrl like a telegraph key: a short press for a dot, a long press for a dash, and a pause between letters.
How do you do Morse code by tapping?
Tap quickly for a dot and hold about three times as long for a dash, then pause before the next letter. Key mode reads that rhythm on the pad, Space or Ctrl, and learns your own timing. To tap out whole messages and keep the text, use the Morse keyboard.
How do I add Morse code to my iPhone keyboard?
Install Google’s Gboard from the App Store, open the Gboard app, tap Languages, Add language and pick Morse Code (US); then hold the globe key in any text box to switch to it. The full steps for iPhone and Android are on the Morse keyboard page, which also lets you practice first.
How do you type E in Morse code?
E is a single dot (.), the shortest code in Morse. In One key mode that is one quick tap; in Two keys mode, press the dot key once and then Send. T is the single dash (-).
What is ABC in Morse code?
A is .-, B is -... and C is -.-., so ABC is .- -... -.-. with a letter gap between them. In One key mode that is tap, hold; hold, tap, tap, tap; hold, tap, hold, tap.
Is there a Morse code clicker online?
Yes: Key mode’s One key works as one. Click or tap the pad, or hold Space or Ctrl; some USB Morse key adapters send Ctrl, so a real key works too. For a key with a timing score and paddles, use the keyer.
Trust and limits
Private by design.
Honest about limits.
On your device
Runs in your browser
Nothing you type or key is sent anywhere, and your best scores and key style are saved on this device only.Know the limits
How presses are read
One key is read from the length of each press, so a very uneven rhythm can still turn a dot into a dash; Two keys is exact. Sound plays through your speaker; on an iPhone, check the silent switch.ITU-R M.1677-1
International Morse
It uses the International Morse code (ITU-R M.1677-1) for the letters A to Z and the digits 0 to 9. Maintained by Translate Morse Code, an independent site; last updated October 2026.