Playfair Cipher

Classic 5×5 digraph substitution cipher.

Keyword Preset Encrypt Decrypt

Text

Output

Key grid:

 A    B    C    D    E 
 F    G    H   I/J   K 
 L    M    N    O    P 
 Q    R    S    T    U 
 V    W    X    Y    Z

No keyword set — using plain A–Z order.

About this tool

Pick a keyword to seed the 5×5 grid (I/J share a square). Encrypts and decrypts uppercase digraphs; identical pairs get an inserted X.