Base32 Decoder — Base32 to Text Online
Decode Base32 text back to readable characters instantly — the standard RFC 4648 format used by TOTP/2FA secret keys. Free, client-side Base32 decoder.
🔒 100% Client-Side Processing
Your data is processed entirely in your browser and never transmitted to any server.
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Common Use Cases
Inspecting a 2FA secret key
Decode an authenticator app's Base32 secret to see its raw byte value while debugging a TOTP implementation.
Reversing legacy encoded identifiers
Recover the original text from Base32-encoded values found in older systems or protocols.
Frequently Asked Questions
- What characters are valid in Base32 input?
- Uppercase A-Z and digits 2-7 only (0, 1, 8, and 9 are deliberately excluded from the alphabet to avoid confusion with O, I, B, and G). Trailing = padding is stripped automatically; anything else is reported as invalid.
- I have a TOTP/2FA secret key — can I decode it here?
- Yes — authenticator app secret keys are Base32-encoded by convention. Paste the secret to see its raw bytes, though the app itself handles the actual time-based code generation.
- Can this also encode text into Base32?
- Yes — use the toggle above to switch to Encode, or go directly to the Base32 Encoder.
- Is my data private when I use this tool?
- Yes. This tool runs entirely in your browser using client-side JavaScript — nothing you type is transmitted to, logged by, or stored on any server. You can safely process confidential text, tokens, or code.