What characters are valid Base32 input?

RFC 4648 Base32 uses uppercase A-Z and digits 2-7. Lowercase letters are accepted and converted automatically. Spaces and padding characters (=) are ignored.

Why are the bits grouped in sets of 8?

Groups of 8 bits represent one byte, which makes the binary output easier to read and compare with byte-oriented data. The underlying conversion still uses 5-bit Base32 characters.

What happens to the padding characters (=)?

Padding equals signs are stripped before decoding. They exist only to align Base32 output to multiples of 8 characters and carry no data bits.

Is Base32 the same as Base64?

No. Base32 uses a 32-character alphabet (A-Z, 2-7) with 5 bits per character. Base64 uses a 64-character alphabet with 6 bits per character. Base32 is case-insensitive and avoids visually ambiguous characters.

Can I decode Google Authenticator keys with this tool?

Yes. Google Authenticator secrets are RFC 4648 Base32 strings. Paste the secret here to see its raw binary form.

What does an invalid character error mean?

It means your input contains a character outside the Base32 alphabet (A-Z, 2-7). Characters like 0, 1, 8, and 9 are not valid Base32 and will trigger this error.

Base32 to Binary Converter

Enter a Base32 string (A-Z and 2-7) and instantly see its full binary bit representation.

Base32 Input

Examples:

Binary Output

Enter a Base32 string and click Convert

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Summary

This tool decodes a Base32-encoded string into its raw binary (bit string) representation following RFC 4648. Each Base32 character maps to exactly 5 bits, so a valid Base32 string expands into groups of 5-bit values displayed as 0s and 1s. Padding characters (=) are handled automatically and stripped from the final binary output, giving you the original bit sequence.

How it works

Enter or paste a Base32 string (letters A-Z and digits 2-7) into the input field.
Padding characters (=) are stripped and the input is uppercased automatically.
Each Base32 character is looked up in the RFC 4648 alphabet and converted to its 5-bit value.
The 5-bit groups are concatenated to form the full binary bit string.
The resulting binary output is displayed grouped in 8-bit bytes for readability.

Use cases

Decode TOTP/2FA secret keys from Base32 to binary to inspect the raw key bytes.
Verify Base32 encoding implementations by checking the decoded bit pattern.
Learn how RFC 4648 Base32 maps characters to 5-bit groups.
Debug authentication libraries that use Base32-encoded secrets.
Convert Base32 checksums or hashes back to their binary representation.
Inspect binary payloads that were transmitted in Base32 form.
Educational exploration of number base conversions.

Frequently Asked Questions

Last updated: 2026-05-28 · Reviewed by Nham Vu