Morse Code: Letter Boundaries, Timing and a Worked Conversion

A short message to try first

Morse code represents characters with short and long signals. You can write those signals as dots and hyphens, but the boundaries between letters matter just as much as the marks. Start with HELLO, check each letter, then add a second word.

This guide uses the supported subset in the Morse Code Converter: A to Z, digits, É and the 13 punctuation characters shown in its chart. It does not claim to decode every operational signal or preserve arbitrary Unicode text. The character codes and relative timing are based on ITU-R M.1677-1, Annex 1.

Encode HELLO WORLD, then check the result

1. Open the converter and choose Text to Morse from Conversion mode.
2. Enter HELLO WORLD. The output is .... . .-.. .-.. --- / .-- --- .-. .-.. -...
3. Look at the first word: H is ...., E is ., each L is .-.., and O is ---.
4. Select Use output as input. This moves the result into the input, selects Morse to Text and recomputes HELLO WORLD.
5. Select Copy output, or select the output field and copy manually if clipboard access fails.

Lowercase input returns uppercase after this round trip. Spaces, tabs and newlines in text become single word boundaries, so this is not a formatting-preserving conversion. If retaining the exact text matters, keep your original message.

Letter boundaries and word boundaries are different

The converter uses whitespace between Morse letters and / between Morse words. A literal slash inside the text is encoded as -..-.. These are different jobs for the same written character.

Four examples you can reproduce in the converter:

• EE is . .: two letters in one word.
• E E is . / .: two separate words.
• E/E is . -..-. .: a literal slash between letters.
• É? is ..-.. ..--..: a supported accent and a punctuation mark.

Multiple spaces still separate letters in this tool. Do not paste three spaces expecting a word break. Tabs and newlines also separate Morse letters. A slash needs a valid word on both sides: leading, trailing or repeated slash separators produce an error.

An unseparated string is not generally safe to split by guessing. For example, ... is S, while . . . is EEE. Continuous operating signals, also called prosigns, are outside this decoder's scope. The sequence ...---... has no internal letter gaps; ... --- ... is the separate letters S, O, S. The tool rejects the continuous sequence rather than guessing what it means.

Hear why spacing changes a message

A dot is the basic time unit. The ITU timing rules specify the relative lengths below. A word gap replaces a letter gap; it is not extra silence added on top.

Relative timing and this tool's fixed playback speed

Part of a signal	Units	Tool duration
Dot	1	100 ms
Dash	3	300 ms
Gap within a letter	1	100 ms
Gap between letters	3	300 ms
Gap between words	7	700 ms

Try EE, then E E. The first takes five units: dot, three-unit letter gap, dot. The second takes nine units: dot, seven-unit word gap, dot. At this tool's speed, those are planned durations of 0.5 and 0.9 seconds, excluding the small audio start offset. They are calculated schedules, not measurements of your device.

Choose Play audio to hear the message or Flash light to see the signal indicator. The 600 Hz tone is a chosen pitch, not a required Morse frequency. Stop playback cancels either sequence; editing, clearing or changing direction also stops it. Audio depends on browser and device support. Light playback uses browser timers and may be delayed in background tabs. Use this for practice, not as emergency signaling equipment.

Fix input errors without changing the message silently

If a character is not in the chart, the converter clears the output and names the unsupported character. It does not discard an emoji, remove an accent or pass unknown text through as Morse. É is supported; other accented letters need a different converter or an explicitly agreed transcription. Keep the original name or message rather than silently altering it.

In decoding mode, use periods and ASCII hyphens. A copied typographic dash or an unknown token is an error. Choose Morse to Text before pasting Morse: the converter does not detect the direction automatically.

Conversion is limited to 10,000 UTF-16 code units. Audio and light playback are limited to 60 seconds. You can still select and copy a longer valid conversion. Reduce the message for playback instead of assuming that a disabled playback button means conversion failed.

Choose an exercise that teaches one rule

For a first exercise, use E (.), T (-) and A (.-) to compare one short signal, one long signal and a letter with an internal gap. Then compare EE with E E to hear the change in boundaries. Finally, encode E/E to see the difference between a text character and a notation separator.

Morse notation is encoding, not encryption. Someone who knows the chart can read it. If your task is to inspect text bytes rather than signal durations, the UTF-8 Binary Text Converter serves a different purpose: it displays bytes instead of Morse letters. Keep those two representations separate when explaining the result.