Tap Code Translator – Letters to Taps and Back

Same text, other sets

Dots ••-••• •-••••• •••-• •••-• •••-••••

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Check it fits: limit characters

Letter for taps by the five-by-five square: the row first, then the column. K is sent as C, so Swap reads 1-3 back as C. Digits and punctuation have no cell: each is kept, set apart by a space.

All 52 codes

Row 1: A, B, C and K, D, E 6

A is 1-1 A: row 1, column 1: one tap, a pause, one tap.
B is 1-2 B: row 1, column 2: one tap, a pause, two taps.
C is 1-3 C: row 1, column 3: one tap, a pause, three taps. Shared with K.
D is 1-4 D: row 1, column 4: one tap, a pause, four taps.
E is 1-5 E: row 1, column 5: one tap, a pause, five taps.
K is 1-3 K: row 1, column 3: one tap, a pause, three taps. K has no cell of its own and is sent as C, so Swap reads this code back as C.

Row 2: F, G, H, I, J 5

F is 2-1 F: row 2, column 1: two taps, a pause, one tap.
G is 2-2 G: row 2, column 2: two taps, a pause, two taps.
H is 2-3 H: row 2, column 3: two taps, a pause, three taps.
I is 2-4 I: row 2, column 4: two taps, a pause, four taps.
J is 2-5 J: row 2, column 5: two taps, a pause, five taps.

Show all 52 codes (41 more)

Row 3: L, M, N, O, P 5

L is 3-1 L: row 3, column 1: three taps, a pause, one tap.
M is 3-2 M: row 3, column 2: three taps, a pause, two taps.
N is 3-3 N: row 3, column 3: three taps, a pause, three taps.
O is 3-4 O: row 3, column 4: three taps, a pause, four taps.
P is 3-5 P: row 3, column 5: three taps, a pause, five taps.

Row 4: Q, R, S, T, U 5

Q is 4-1 Q: row 4, column 1: four taps, a pause, one tap.
R is 4-2 R: row 4, column 2: four taps, a pause, two taps.
S is 4-3 S: row 4, column 3: four taps, a pause, three taps.
T is 4-4 T: row 4, column 4: four taps, a pause, four taps.
U is 4-5 U: row 4, column 5: four taps, a pause, five taps.

Row 5: V, W, X, Y, Z 5

V is 5-1 V: row 5, column 1: five taps, a pause, one tap.
W is 5-2 W: row 5, column 2: five taps, a pause, two taps.
X is 5-3 X: row 5, column 3: five taps, a pause, three taps. Also used to break up sentences.
Y is 5-4 Y: row 5, column 4: five taps, a pause, four taps.
Z is 5-5 Z: row 5, column 5: five taps, a pause, five taps.

The same square in dots 26

A is •-• A: one tap, a pause, one tap.
B is •-•• B: one tap, a pause, two taps.
C is •-••• C: one tap, a pause, three taps.
D is •-•••• D: one tap, a pause, four taps.
E is •-••••• E: one tap, a pause, five taps.
F is ••-• F: two taps, a pause, one tap.
G is ••-•• G: two taps, a pause, two taps.
H is ••-••• H: two taps, a pause, three taps.
I is ••-•••• I: two taps, a pause, four taps.
J is ••-••••• J: two taps, a pause, five taps.
K is •-••• K: one tap, a pause, three taps.
L is •••-• L: three taps, a pause, one tap.
M is •••-•• M: three taps, a pause, two taps.
N is •••-••• N: three taps, a pause, three taps.
O is •••-•••• O: three taps, a pause, four taps.
P is •••-••••• P: three taps, a pause, five taps.
Q is ••••-• Q: four taps, a pause, one tap.
R is ••••-•• R: four taps, a pause, two taps.
S is ••••-••• S: four taps, a pause, three taps.
T is ••••-•••• T: four taps, a pause, four taps.
U is ••••-••••• U: four taps, a pause, five taps.
V is •••••-• V: five taps, a pause, one tap.
W is •••••-•• W: five taps, a pause, two taps.
X is •••••-••• X: five taps, a pause, three taps.
Y is •••••-•••• Y: five taps, a pause, four taps.
Z is •••••-••••• Z: five taps, a pause, five taps.

How this list was compiled: The five-by-five square, the rule that a letter is tapped as its row and then its column, the rule that K is sent as C, the use of X between sentences, the other name knock code and the worked example hello are as given in https://en.wikipedia.org/wiki/Tap_code, read on 2026-10-01. A second published account of the code, a public broadcaster's history article at https://www.pbs.org/wgbh/americanexperience/features/honor-tap-code/, read the same day, gives the same five-by-five square, the same order (row, then column), the same two test letters (W is 5-2 and H is 2-3) and the same rule for K. The square is from the first source, and the test letters of the second were checked against it; the 52 rows are every letter once as numbers and once as dots. The dots and the hyphen for the pause are this page's own way of writing taps down. Licence: own work (facts from Wikipedia, CC BY-SA 4.0, restated in this site's own words)

How it works

This tap code translator writes each letter as two numbers from a five-by-five square: its row, then its column. H is 2-3, tapped as two knocks, a pause and three knocks.

Read the full guide

Numbers or dots

The first row writes the taps as numbers and the second as dots, so H is 2-3 or ••-•••. The hyphen is the short pause inside a letter, a space parts two letters, and a slash parts two words.

The square

The alphabet sits in five rows of five, A to E on the first and V to Z on the last. That makes 25 cells for 26 letters, so K is sent as C. Wikipedia notes that a listener needs only the first letter of each row, A, F, L, Q and V: count the first taps down that list, then count along the row.

X, which is 5-3, breaks up sentences.

Questions and answers

How does tap code work?

Every letter is two counts read off a five-by-five square of the alphabet. Tap the number of its row, pause, then tap the number of its column. B is one tap, a pause and two taps.

Why is there no K in tap code?

Twenty-six letters do not fit in 25 cells, so K is sent as C. Both sources this page was checked against give that rule. Kite is tapped exactly as cite, and Swap reads it back with a C.

Is tap code the same as Morse code?

No. Morse code gives each letter its own pattern of short and long signals. Tap code has one kind of tap and counts them. Wikipedia records that its messages are longer but that it is simpler to learn.

What is the knock code?

Another name for the tap code. Wikipedia traces the idea of a letter square back to ancient Greece's Polybius square.