Encode data as Base32 (RFC 4648) using the case-insensitive A-Z 2-7 alphabet found in TOTP authenticator secrets, DNS records and Onion addresses. The base32hex variant is supported too.
Show calculation steps
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How to use the Base32 Encoder
- Paste the text or secret you want to encode.
- Choose the variant: standard RFC 4648 (A-Z and 2-7) for TOTP and most uses, or base32hex when a system asks for the 0-9 A-V alphabet.
- Adjust padding and letter case if the target system is fussy about them.
- Click "Encode to Base32" and copy the result.
Frequently asked questions
Why does Base32 exist when Base64 is shorter?
Because Base32 is case-insensitive and avoids easily confused characters, so it survives being spoken aloud, handwritten, typed on a phone keypad or stored in a case-insensitive system such as DNS. The trade-off is size: Base32 output is about 60 percent larger than the input, versus 33 percent for Base64.
Where will I actually meet Base32?
Most commonly in two-factor authentication: the secret behind an authenticator app QR code is Base32. It also appears in Tor onion addresses, some DNS record formats and in the base32hex form inside NSEC3 records.
Why are there no 0, 1, 8 or 9 in the alphabet?
Standard Base32 uses A-Z plus the digits 2-7 precisely because 0 and 1 are visually confusable with O and I. Removing them makes transcription errors far less likely – the same motivation behind Base58.
What is the base32hex variant for?
It uses 0-9 followed by A-V, an ordering that preserves the sort order of the underlying data. That property matters in DNSSEC NSEC3 records, where records must remain sortable after encoding.
