Use this decoder when the input is known to use the named encoding or classical cipher and you need to recover its bytes, symbols, numbers, or text deterministically.

Ciphertext

Required string input.

Alphabetic key

Required string input.

Decrypt ASCII-letter Vigenère ciphertext with its repeating alphabetic key; case and nonletters are preserved. This is a historical cipher, not modern encryption. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Plaintext

The resulting plaintext returned as a string.

• Decoding cannot reliably identify an unknown format or repair arbitrary corruption. Alphabet variants, padding, whitespace, character encodings, byte order, framing, cipher keys, and malformed-input policies must match the producer.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Confirm the format from metadata or a specification, preserve the original input, and validate decoded length or checksums where available. Treat decoded untrusted content as data rather than executable markup or code.

• Grade 1 Braille Decoder

  Decode uncontracted English Unicode Braille letters, digits, and common punctuation. Numeric and capital indicators are interpreted; contracted Braille is not supported.

• Bacon Cipher Decoder

  Decode five-symbol Bacon cipher groups back into letters A–Z.

• Base58 Decoder

  Decode Base58 (Bitcoin alphabet) text into its UTF-8 source text.