Morse Code Calculator - Encode, Decode, and Time

A Morse code converter turns readable characters into the dots and dashes of International Morse code and turns Morse strings back into readable text. The same calculator handles distress calls, ham radio call signs, and short text notes without reformatting.

• • Decoding amateur radio call signs: Read short fragments from CW skimmer output or instructor transcripts without a printed chart.
• • Translating SOS and other distress signals: Turn the universal ... --- ... call into text, or build the same string from a message.
• • Teaching the International Morse table: Show how each letter, digit, and punctuation mark maps to a fixed dit and dah sequence.
• • Encoding short messages for offline use: Generate a flashable Morse string for a flashlight, mirror, or whistle signal.

The calculator uses International Morse code from ITU-R M.1677-1. Letter matching is case-insensitive, so 'Hello' and 'hello' produce the same output.

The same one-symbol-per-character pattern shows up in the ASCII converter, which maps every letter to a fixed 0-127 code point so the same character can be encoded in decimal, hex, octal, or binary.

The converter walks the input one character at a time, reads the matching symbol from the International Morse table, and renders it in the chosen style. Encoding works on a plain text string; decoding works on a Morse string split by the chosen separators.

• textInput: The text to encode. Letters are matched case-insensitively.
• morseInput: A Morse string to decode. Tokens are split on the chosen separators.
• letterSeparator: Character between letters: space, slash, or pipe.
• wordSeparator: Character between words: slash, pipe, or double space.
• symbolStyle: Whether the output uses .- notation or the named dit and dah wording.
• mode: Encode walks the text and outputs Morse. Decode walks the Morse and outputs text.

Encoding is the same regardless of separator or symbol style; only the formatting changes. The dot-dash style writes each symbol as .- notation; the dit-dah style writes the named wording so the output reads as a spoken cadence. Decoding is the reverse: tokens are split, normalized back to dot-dash, and looked up in the inverse table.

According to ITU-R M.1677-1 International Morse code recommendation, the International Morse code assigns '.-' to the letter A, '--' to M, and '... --- ...' to the SOS distress signal, with one word defined as 50 dot units under the PARIS timing standard.

The same kind of symbol rewriting applies the other way around, and the binary to text converter decodes a fixed-width binary string back to text the same way the Morse code converter reads the inverse table.

Four small ideas explain every result the Morse code converter shows.

When the input goes past the base table, the calculator does not silently fail; it flags the out-of-table character so the user can see exactly which character was not encoded.

These four ideas line up with what the calculator actually does: read a symbol from the table, format it in the chosen style, and rebuild the same string when the separators are consistent, which is the same one-symbol-per-letter pattern the NATO phonetic alphabet calculator uses for spoken call signs.

Five short steps cover both Encode and Decode without any setup.

1. 1 Pick the conversion mode: Use Encode to turn text into Morse. Use Decode to turn Morse back into text.
2. 2 Choose the input field that matches your mode: Encode reads the Text Input field. Decode reads the Morse Code Input field.
3. 3 Select the letter and word separators: A space is the most readable letter separator. A slash is the most common word separator. Pick distinct values so the parser can tell boundaries apart.
4. 4 Choose the symbol style: Use dot and dash for the canonical .- notation, or dit and dah for the named wording that reads like a spoken cadence.
5. 5 Read the result, counts, and duration: The result panel shows the encoded Morse string or the decoded text, plus the dit count, the dah count, and the estimated duration at 20 WPM.

If you paste the text 'Hello' with Encode mode and a space letter separator, the calculator reads H, E, L, L, O from the table, joins them with spaces, and shows '.... . .-.. .-.. ---'. Switching the symbol style to dit-dah rewrites the same string with the dot and dash names spelled out, which is the form a CW practice script reads aloud.

A purpose-built Morse code converter keeps the table consistent, the separators consistent, and the timing estimate readable.

• • One tool for both directions: Encoding and decoding share the same input fields, separators, and symbol style, which makes round-trip testing easy.
• • Configurable letter and word separators: A space, slash, pipe, or double space fits the format used by CW practice apps and reference charts.
• • Visible dit, dah, and duration counts: The result panel shows how many dits and dahs the message contains and the estimated air-time at 20 WPM.
• • Tolerant of mixed case and dit-dah wording: Letters are matched case-insensitively, and the decoder accepts the named dit and dah wording as well as the canonical dot and dash symbols.
• • Standardized against ITU-R M.1677-1: The lookup table matches the symbols and timing that ITU-R M.1677-1 publishes.

The result panel puts the primary value at the top and the supporting counts below it, the same way the rest of the calculator's results read.

When the encoded output needs to be sent over a binary channel or a chat log, the Caesar cipher shifter shows how the same letter-by-letter transformation pattern looks when it shifts letters through a substitution alphabet instead of a Morse table.

Three variables determine what the result looks like, and two limitations tell you when to reach for a different tool.

• • The base table covers 26 letters, 10 digits, and 16 punctuation symbols. Accented letters, emoji, and CJK characters are not in the table and are surfaced as warnings rather than silent errors.
• • The converter does not handle Morse prosigns (procedural signals such as AR, SK, BT, or KN) that combine multiple letters into a single transmitted symbol.

The base table matches the same 26 letters, 10 digits, and 16 punctuation symbols that the rest of the international references publish.

According to ARRL Morse code reference, the PARIS standard sets one word at 50 dot units so a dit is the time unit, a dah is three dit units long, and the gap between letters is three dit units.

When the encoded output is meant for a different code table, the Base64 encoder decoder encodes text into a binary-safe character set, and the same one-symbol-per-character pattern is what the Morse code converter uses with dits and dahs.