Base32 Encode / Decode

Encodes and decodes Base32 (RFC 4648).

Base32 Encode / Decode converts text to and from Base32 using the standard RFC 4648 alphabet (A-Z and 2-7). Switch between encode and decode modes to turn UTF-8 text into a padded Base32 string or read an existing Base32 string back into plain text. It is handy whenever you need a case-insensitive, alphanumeric-only encoding that survives copy-paste and URLs better than Base64.

Common uses

  • Encode short text into the RFC 4648 Base32 alphabet for use in tokens or identifiers
  • Decode a Base32 string copied from logs, config files, or API responses back to readable text
  • Inspect Base32-encoded values where Base64 is undesirable because of case sensitivity
  • Produce padded Base32 output (= padding to an 8-character boundary) for systems that expect RFC 4648 formatting
  • Quickly check whether a string is valid Base32 by attempting to decode it

FAQ

Is my data sent to a server?

No. Encoding and decoding run entirely in your browser using JavaScript, and nothing you type is uploaded or stored on any server.

Which Base32 variant does this use?

It uses the standard RFC 4648 alphabet (A-Z and digits 2-7) with = padding so the output length is a multiple of 8. It does not support the extended hex (base32hex) or z-base-32 alphabets.

Is decoding case-sensitive?

No. On decode the input is uppercased first, trailing = padding is stripped, and whitespace is removed, so lowercase or spaced-out Base32 still decodes correctly.

What happens if the input contains an invalid character?

Decoding throws an error naming the offending character. Only letters A-Z and digits 2-7 (plus padding and whitespace) are valid; characters like 0, 1, and 8 are not part of the alphabet.

How is text interpreted during encoding?

Input text is encoded as UTF-8 bytes before conversion, so multi-byte characters are handled correctly. Decoding reverses this and returns the bytes as UTF-8 text.

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