Base32 encode / decode

Base32 reads the input five bytes (40 bits) at a time and splits them into eight 5-bit groups, mapping each group to one of 32 printable characters. When the final block is short, = padding fills it out to a multiple of eight characters.

The cost is size: output is about 60% larger than the input, versus 33% for Base64. The benefit is robustness — the alphabet omits 0/O and 1/l confusion and ignores case, so it survives transcription, phone dictation, and case-mangling middleware.

Reach for Base32 when a human or a case-insensitive system touches the encoded string:

• TOTP / 2FA secrets — the otpauth:// standard mandates Base32.
• DNS labels and case-insensitive identifiers — Base32 fits the limited charset.
• Manually-entered keys — license codes, recovery keys, anything read off a screen.

Stick with Base64 when size matters and the channel is machine-to-machine — JSON payloads, data URIs, and email attachments are all better served by the denser encoding.

1. Choose Encode to turn text into Base32, or Decode to recover text.
2. Paste your input into the left pane — UTF-8 text or a Base32 string.
3. Toggle = padding off if your target rejects it (some TOTP secrets and URLs do).
4. Copy the result with the Copy button or ⌘/Ctrl+Enter, or hit Swap to feed it back as input.

A few things trip people up:

• Confusing Base32 with Base32hex. This tool uses the standard RFC 4648 §6 alphabet (A–Z 2–7), not the extended-hex variant (0–9 A–V) used by some DNSSEC records.
• Expecting it to be encryption. Base32 is fully reversible by anyone — never use it to hide secrets.
• Case sensitivity. Decoding is case-insensitive, but some downstream parsers expect uppercase. This tool emits uppercase by default.

Everything happens locally. The codec is a few dozen lines of JavaScript running on the bytes of your input — there is no server round-trip, no logging, and no analytics on the content you paste. Because the work is client-side, you can use it on confidential recovery keys or 2FA secrets without that data ever leaving the tab. Close the tab and the input is gone.