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Client-side ProcessingUpdated 2026-02-11Report issue

Runs fully in your browser. Inputs stay on your device. See recent fixes on changelog.

Vigenere Cipher Encoder / Decoder

Encode and decode text using the Vigenere polyalphabetic cipher.

FreeRuns in browservigenere ciphervigenere decoder

Uses a keyword to apply different Caesar shifts per character.

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Cmd/Ctrl+Enter Primary actionCmd/Ctrl+Shift+L Load sampleCmd/Ctrl+Shift+X Clear/resetCmd/Ctrl+Shift+C Copy result

About Vigenere Cipher Encoder / Decoder

Encode and decode text using the Vigenere polyalphabetic cipher. Encode and decode text with the Vigenere cipher online for free. Polyalphabetic substitution using a keyword to apply different Caesar shifts per character. Implements standard encoding and decoding algorithms that produce output compatible with all major programming languages and platforms. Supports both encoding and decoding in a single interface. Everything runs client-side in your browser for maximum speed and privacy — no data is sent to any server, and no signup is required.

Related tools: Caesar Cipher Encoder / Decoder, Atbash Cipher Encoder / Decoder, Rail Fence Cipher Encoder / Decoder

How to Use Vigenere Cipher Encoder / Decoder

  1. Enter text or data in the input field.
  2. Click Encode or Decode depending on your goal.
  3. Copy the output to your clipboard.

Frequently Asked Questions

What is Vigenere Cipher Encoder / Decoder?
Encode and decode text with the Vigenere cipher online for free. Polyalphabetic substitution using a keyword to apply different Caesar shifts per character.
What encoding standards are used?
This tool follows the official encoding specifications, including RFC standards where applicable. The implementation matches widely-used libraries so the output is compatible with other systems and programming languages.
Can I encode binary data?
The tool primarily handles text input, but many encoding formats such as Base64 are designed to represent binary data as text. You can paste Base64-encoded binary data for decoding or encode text into a binary-safe format.
Is the encoding reversible?
Yes, all encoding operations provided by this tool are fully reversible. You can encode text and then decode it back to get the exact original content without any data loss.
Is Vigenere Cipher Encoder / Decoder free to use?
Yes, encoding and decoding are completely free with no usage limits. The tool runs in your browser and requires no registration.
Is my data safe when using Vigenere Cipher Encoder / Decoder?
Yes, all encoding and decoding happens locally in your browser. No data leaves your device, so your input remains completely private.