Base32 Decode and Encode
Convert text to RFC 4648 Base32 or decode it back. Spaces and missing padding are fine; lowercase is accepted.
How Base32 works
Base32 reads the input 5 bits at a time. Five bits give 32 possible values, each mapped to one character in ABCDEFGHIJKLMNOPQRSTUVWXYZ234567. Five bytes (40 bits) become exactly eight characters, and shorter endings are padded with = to a multiple of eight.
A security note: an authenticator secret is effectively a password. Decoding it here is safe because nothing leaves your browser, but never paste one into a site that sends it to a server. For general-purpose encoding, Base64 is more compact.
Questions people ask
Where is Base32 used?
Most visibly in two-factor authentication: the secret behind a TOTP QR code (the otpauth:// link) is Base32. It is also used in Tor onion addresses, some file-sharing hashes and DNS-safe identifiers.
Why use Base32 instead of Base64?
Base32 uses only uppercase letters A–Z and digits 2–7, so it survives case-insensitive systems and is easier to read aloud or type. It avoids 0, 1 and 8, which look like O, I/L and B. The cost is size: output is 60% larger than the input, against 33% for Base64.
Is this the RFC 4648 alphabet?
Yes, the standard alphabet with = padding. Crockford’s Base32 and the “base32hex” variant use different alphabets and will not decode correctly here.