Vigenère Cipher
Encrypt and decrypt text with a keyword cipher.
Quick answer: enter your details below and click Encrypt — your result appears instantly, right here in your browser. Nothing you enter is uploaded or stored.
V
Text & Writing
Enter your details below.
How to use
- Type your message into the box.
- Enter a keyword and choose Encrypt or Decrypt.
- Click Encrypt and copy the result.
About this tool
Vigenère Cipher encrypts text using a keyword, shifting each letter by a different amount as the keyword repeats. Unlike a single fixed shift, the changing shifts hide letter patterns, which made this cipher famously hard to break by hand.
Frequently asked questions
Do spaces and punctuation get encrypted?
No. They pass through unchanged, and the keyword only advances on letters, so the recipient needs the same rule to decode.
Does a longer keyword make it stronger?
Yes. A longer, less predictable keyword produces more varied shifts and is harder to crack than a short repeated word.