Base32 Decode

Fast and Secure Base32 Decoding in your Browser

Chars

Bits

Bytes

Decoded Text

Enter your data

Error

Please enter a valid Base32 string (A-Z, 2-7).

Understanding Base32 Decoding

Verify TOTP Secrets

Decode a Base32 secret key to confirm it matches the value provisioned by an authenticator app or identity provider.

DNS & Filename Data

Reverse Base32-encoded values found in DNS TXT records, filenames, or case-insensitive storage systems.

Debugging

Quickly inspect what a Base32-encoded payload actually contains without writing a script.

Data Integrity

Confirm the decoded output matches expectations before using it in downstream systems.

How Base32 Decoding Works

Each Base32 character represents 5 bits, decoded from the alphabet A-Z and 2-7. Groups of 8 characters (40 bits) map back to 5 original bytes; trailing '=' characters are padding and are ignored during decoding.

Key Takeaways

RFC 4648 Standard: This tool decodes the standard Base32 alphabet (A-Z, 2-7), ignoring trailing '=' padding.
Invalid Characters: Any character outside A-Z and 2-7 will raise a clear validation error.
Client-Side Only: All decoding happens locally in your browser — no data is ever sent to a server.

Base32 Decode - Convert Base32 to Text Online