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How to use Vigenère Cipher

Get the best out of Vigenère Cipher: every option explained, a worked example, and what to check when the output is not what you expected.

Updated July 31, 2026

What it does

Encode or decode text with a keyword-based Vigenere cipher while preserving case and spacing. It runs entirely in your browser — your input never leaves your device.

Options

Every setting this tool exposes, straight from the code that validates it.

OptionTypeDefaultWhat it does
texttextText to encode/decode. Required.
keytextCipher key (letters). Accepts at least 1 characters. Required.
modeone of: encode, decodeencodeDefaults to encode.

Worked example

Run these settings on the tool page:

  • text: hello
  • key: my-secret
  • mode: encode

You get:

tcdpq

Getting the result you want

Most of the control here is in the options above. If the output is not what you expected, the setting to check first is mode — those change the shape of the output rather than the input it accepts.

Troubleshooting

  • Nothing happens / the output stays empty. text, key are required — the tool waits until you provide them.
  • A value is rejected. key accepts at least 1 characters. Anything outside that is refused rather than silently clamped.
  • It is slow on very large input. Everything runs in your browser, so speed depends on your device. Very large inputs are best split up, or run through the API where the work happens on our servers.

Automating it

The same logic is available as a REST endpoint, so you can run it from a script, a CI job or your own app.

Bash
curl "https://api.toolsxpo.com/v1/vigenere-cipher" \
  -H "Authorization: Bearer $TOOLSXPO_KEY"

It costs 1 credit per successful call. See the full endpoint reference, or try it in the playground.

Tools covered here

Vigenère Cipher

Security

security

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