How do I decode Base32 back to readable text?

Paste your Base32-encoded string into the decoder input field and the tool will instantly convert it back to the original readable text. The decoder automatically handles both padded (with = characters) and unpadded Base32 strings. It is also case-insensitive, converting all input to uppercase automatically before decoding. If the Base32 string is invalid or contains characters outside the allowed set (A-Z and 2-7), the decoder will display an error message explaining the issue. The decoded text preserves all original characters including special symbols, line breaks, Unicode characters, and emojis exactly as they were before encoding.

What if my Base32 string has invalid characters?

Base32 only accepts uppercase letters A through Z and digits 2 through 7, plus the padding character (=). If your string contains any other characters—including 0, 1, 8, 9, or lowercase letters—the decoder will show an error identifying the invalid character. Common mistakes include copying Base64 strings (which use different characters), including whitespace or line breaks (which are automatically removed), or mixing up similar-looking characters. The tool will tell you exactly which character is invalid so you can correct it. Some Base32 variants use different alphabets, so ensure your string uses the standard RFC 4648 alphabet this tool supports.

Why does my TOTP/2FA secret not decode correctly?

TOTP secrets from Google Authenticator, Authy, or similar apps are Base32-encoded and should decode perfectly. If you are having issues: 1) Ensure you copied the entire secret including any padding (= characters), 2) Remove any spaces or line breaks that may have been added during copying, 3) Verify the secret is Base32 and not Base64 (Base64 uses lowercase letters and +/ characters), 4) Some apps display secrets with spaces for readability—remove all spaces before decoding, 5) Check that you copied the secret correctly without missing or extra characters. The decoded output should be binary data, not necessarily readable text, since TOTP secrets are random bytes.

Can Base32 strings be decoded without padding?

Yes! This decoder handles both padded and unpadded Base32 strings correctly. Padding (equals signs at the end) is technically optional per RFC 4648 specification. Some implementations include padding to make string length a multiple of 8 characters, while others omit it to save space. For example, "JBSWY3DP" and "JBSWY3DP" (no padding needed) are both valid, and "JBSQ====" can also be written as "JBSQ" without padding. The decoder automatically calculates where data ends regardless of padding presence. If you encounter Base32 without padding, it will decode just fine.

Is Base32 case-sensitive when decoding?

No! Base32 is completely case-insensitive. The standard RFC 4648 alphabet uses only uppercase letters A-Z, but decoders should accept lowercase input as well. This decoder automatically converts all letters to uppercase before processing, so "jbswy3dp", "JBSWY3DP", or even "JbSwY3Dp" will all decode to the same result. This case-insensitivity is one of Base32's key advantages over Base64—it makes manual entry much easier since users don't have to worry about capitalization. However, the canonical form and what most encoders produce is always uppercase.

What does the decoded Base32 output represent?

The decoded output depends on what was originally encoded. If text was encoded, you will get readable text back. If binary data (like a file or TOTP secret) was encoded, the output may contain non-printable characters or appear as gibberish. TOTP/2FA secrets are typically 16-32 bytes of random binary data—when decoded, they look like random characters because they are raw bytes, not meant to be readable text. If you are decoding a TOTP secret to verify it, the decoded bytes are correct even if they do not display as readable text. The important part is that the binary data can be used by authenticator apps to generate codes.

Why is Base32 used instead of Base64 for authentication?

Base32 is preferred for TOTP/2FA because it is optimized for human readability and manual entry. Unlike Base64, Base32 avoids ambiguous characters—there is no confusion between 0/O, 1/I/l, or case sensitivity (a/A). When QR code scanning fails, users must manually type the secret into their authenticator app. Base32's alphabet (A-Z, 2-7) contains only visually distinct characters, reducing typing errors. Additionally, Base32 is case-insensitive, so users don't need to worry about capitalization. While Base64 is more space-efficient (33% overhead vs Base32's 60%), the human-friendliness of Base32 makes it ideal for authentication scenarios where manual entry is sometimes required.

Can I decode Base32-encoded files?

Yes, but the decoded output will be binary data, not readable text (unless the original file was text). When you decode a Base32 string that represents a file, you get the raw bytes back. This tool displays the output as text, so binary files may show strange characters or symbols. For proper file decoding, you would need to save the decoded bytes as a binary file rather than viewing as text. If you encoded a text file, the decoded output will be readable. If you encoded an image, PDF, or other binary format, the decoded output contains the correct bytes but will not be human-readable in a text field.

Is my data safe when using this Base32 decoder?

Yes! All decoding happens entirely in your browser using JavaScript. Your data never leaves your device and is not uploaded to any server. The tool processes everything locally on your computer or mobile device, ensuring complete privacy. Once you close or refresh the page, all data is cleared from browser memory. This client-side approach is secure for decoding sensitive data like TOTP secrets, credentials, or authentication keys, though remember that Base32 is encoding, not encryption—anyone with the Base32 string can decode it using any Base32 decoder.

What is the difference between Base32 and Base64 decoding?

Base32 and Base64 use different character sets and are not interchangeable. Base32 uses only A-Z and 2-7 (32 characters total), while Base64 uses A-Z, a-z, 0-9, +, and / (64 characters total). You cannot decode a Base64 string with a Base32 decoder—it will fail because Base64 contains invalid characters for Base32 (like lowercase letters, 0, 1, +, /). Similarly, decoding Base32 with a Base64 decoder produces wrong results. Always use the correct decoder for your encoded data. If your string contains lowercase letters or +/ symbols, it is Base64. If it only has uppercase letters A-Z and digits 2-7, it is Base32.

Free Base32 Decoder Online

Decode Base32 strings back to readable text instantly. Perfect for decoding TOTP/2FA secrets and authentication keys. 100% free, secure, and works in your browser.

EncodeDecode

Base32 string to decode

Decoded result

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