Playfair Cipher
Encrypt and decrypt text using the Playfair cipher, locally in your browser.
🔒 Your data is processed locally in your browser and is never uploaded to our servers.
How it works
The Playfair cipher uses a 5×5 letter grid generated from a keyword. The letters I and J share the same position. The plaintext is divided into pairs and each pair is transformed according to its position in the grid.
Examples
A common example uses the keyword MONARCHY.
The keyword is used to create the Playfair 5×5 matrix before encryption or decryption.
Security notes
Playfair is a historical classical cipher and is not secure against modern cryptanalysis. Do not use it for real confidential information.
FAQ
Why are I and J combined?
The traditional Playfair cipher uses a 5×5 grid, so I and J normally share the same cell.
What happens to repeated letters?
Repeated letters in a pair are separated with the letter X. For example, BALLOON becomes BA LX LO ON.
Are spaces preserved?
Playfair operates on alphabetic characters. Spaces, numbers and punctuation are removed before processing.