Vigenère Cipher

Encode and decode the Vigenère cipher using a keyword. This classic polyalphabetic cipher shifts each letter by a different amount based on your key, making it stronger than a simple Caesar cipher. Great for puzzles, CTFs, and learning cryptography.

Built for vigenère cipher workflows and closely related tasks like vigenere cipher.

Enter text

5 chars1 words

Options

Mode

Keyword (letters only)

Cipher outputLive preview

Rijvs

Ctrl+Enter to copy | Ctrl+Z to undo

Example usage

Example input

Hello

Example output

Rijvs

Batch Processing

Enter multiple inputs, one per line. Each line will be processed separately.

Input (one per line)

Results

Why this tool?

All tools run entirely in your browser no uploads, no tracking.. All processing happens in your browser so no text ever leaves your device.

Quick tips

•Outputs update live as you type.
•Use the sticky copy button to grab results quickly.
•Bookmark this page for fast access.

encoding cluster

Explore the full tool family, supporting guides, and priority pages around this workflow.

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How it works

Enter the text you want to encode or decode.
Type a keyword made of letters — it repeats across your text to shift each letter.
Switch to decode and use the same keyword to recover the original message.

Use cases

Solve and create Vigenère puzzles and CTF challenges.

Learn how polyalphabetic ciphers improve on Caesar shifts.

Send keyword-protected coded messages for games.

Decode Vigenère text when you know the keyword.

Encoding

Explore all encoding and decoding tools

Jump back to the cluster hub to browse the full tool family, the strongest money pages, and the supporting guides tied to this workflow.

Browse Encoding

Related tools in this cluster

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Letters to Numbers Converter

Map letters A-Z to numbers 1-26 instantly. This letter to number translator uses the A1Z26 cipher to transform alphabetical characters into their corresponding numeric positions. Convert words to numbers by mapping each letter to its alphabet position (A=1, B=2, C=3, etc.).

Text to Hex

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Hex to Text

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Text to Binary

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Text to Base64

Encode text into Base64 safely. This Text to Base64 converter transforms plain text into Base64-encoded strings using UTF-8 encoding for secure data transmission.

Supporting guides

Numbers to Letters Calculator Explained

Learn how A1Z26 decoding works, which separators to use, and how to turn number strings into readable words quickly.

Text to Hex: Fast UTF-8 Examples for Developers

Understand how text maps to bytes and hex values with clear UTF-8 examples you can copy and test.

Conversion History

FAQ

What is the Vigenère cipher?

It is a classic cipher that uses a repeating keyword to shift each letter by a different amount, making it harder to crack than a single-shift Caesar cipher.

Do I need the keyword to decode?

Yes. Decoding requires the same keyword that was used to encode. Without it, the output will not be readable.

What characters does it change?

Only letters are shifted, and their case is preserved. Spaces, numbers, and punctuation are kept unchanged.