Read Morse light patterns

The light carries marks and gaps

In a simple demonstration, light on represents a signal mark and light off represents its gaps. Dots and dashes differ by duration, not brightness. A viewer needs the pauses inside a character, between characters and between words to reconstruct the text.

The screen-flash tool uses the same International timeline as audio. It is a browser display demonstration and cannot verify visibility, reception or interpretation at a distance. Visibility depends on equipment and conditions, so this page does not give unsupported range claims.

Compare a familiar letter

For H, watch four short flashes with short dark intervals. For I, watch two. In HI, a longer dark interval separates H from I. A written transcript .... .. gives the same grouping explicitly; a continuously lit mark or an omitted gap changes what the viewer can distinguish.

Keep an accessible written or audio alternative available when using a light pattern for a lesson. The aim is identifying the code, not requiring a particular sensory channel. A screen demonstration should provide a clear stop control and respect the viewer’s preference about flashing content.

Distinguish a demonstration from a distress signal

The continuous SOS pattern has three short marks, three longer ones and three short ones without letter gaps. Typing SOS into the normal text tool produces separate S, O and S characters. Use the dedicated reference to compare those rhythms accurately.

An explanation of the pattern does not establish that any light device is suitable for an emergency or that a recipient has seen it. This page focuses on reading Morse timing. It does not replace the appropriate communication equipment, instructions or response procedures for a real setting.

Worked examples

These patterns use International Morse. Spaces separate letters; / separates words. A slash in the original text is encoded as -..-.

HI

.... ..

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