Which Base32 alphabet does this use?

It uses the standard RFC 4648 alphabet: the uppercase letters A–Z and the digits 2–7, with = for padding. This is the same encoding used by TOTP authenticator secrets.

Why is Base32 used instead of Base64?

Base32 is case-insensitive and avoids easily confused characters, so it survives being typed by hand, spoken aloud or stored in case-insensitive systems like DNS. It is less compact than Base64 but more robust.

No — encoding and decoding happen entirely in your browser with no network requests.

Base32 Encoder & Decoder

Base32 encoder and decoder (RFC 4648)

Base32 encodes binary data using 32 case-insensitive characters — the uppercase letters A–Z and the digits 2–7 — defined in RFC 4648. Because it avoids ambiguous characters and is case-insensitive, it is ideal for values that may be typed by hand, such as TOTP two-factor secrets and DNS-safe identifiers.

Choose encode to turn text into Base32, or decode to convert a Base32 string back to text. The result updates instantly and stays entirely in your browser.