Base32 Decoder

Base32 Decoder is a free online tool that converts Base32-encoded strings back into their original human-readable text. Base32 encoding represents binary data using a 32-character alphabet (A–Z and 2–7), making it suitable for environments where only uppercase letters and a limited set of digits are safe to transmit. Decoding reverses this process, restoring the original plaintext from the encoded representation.

Developers frequently encounter Base32-encoded data in authentication systems (such as TOTP secrets used by Google Authenticator), file naming schemes, and data transfer protocols that require case-insensitive encoding. Having a reliable, instant decoder on hand saves time and eliminates the need to write one-off scripts just to inspect an encoded value during debugging or integration work.

Using the tool is straightforward: paste your Base32-encoded string into the input field and the decoded output appears immediately. Valid Base32 input consists of uppercase letters A through Z and the digits 2 through 7, often padded with one or more '=' characters at the end to align the data to a multiple of 8 characters. The tool handles both padded and unpadded input gracefully.

The output will be the original UTF-8 text (or raw string) that was encoded. If the input contained encoded binary data rather than plain text, some characters in the output may appear as symbols or be unreadable — this is expected behavior and not a bug. Always ensure the source of your Base32 string used standard RFC 4648 encoding for best results.

Common edge cases to be aware of: Base32 is case-insensitive in most implementations, so lowercase input is typically normalized to uppercase before decoding. If you receive an error, check for characters outside the valid alphabet (such as 0, 1, 8, or 9) which are not part of Base32 and indicate a corrupted or misidentified string — it may actually be Base64 or another encoding scheme.