Base32 Encoder / Decoder

Base32 encodes binary data using 32 printable ASCII characters (A-Z, 2-7). It's commonly used in TOTP (Time-based One-Time Passwords), DNS labels, and file systems that are case-insensitive. The encoded output is about 60% larger than the original.

Base64 uses 64 characters (A-Z, a-z, 0-9, +, /) and produces about 33% overhead. Base32 is more compact in character set but less efficient in size. Base32 is case-insensitive (all uppercase), making it better for QR codes and human-readable keys.

Base32 is case-insensitive and avoids visually similar characters (0/O, 1/I/L). This makes it better for human-readable scenarios like product keys, software licenses, and OTP secrets. Base64 is more compact but case-sensitive and includes + and / which need URL escaping.

Standard Base32 (RFC 4648) uses A-Z and 2-7 (32 characters total). The '=' character is used for padding. The extended hex alphabet uses 0-9 and A-V. Base32 encodes 5 bits per character, so 5 bytes (40 bits) become exactly 8 Base32 characters.

TOTP/HOTP two-factor authentication secrets, DNSSEC key digests, product license keys, and geohash coordinates all commonly use Base32 encoding. It's chosen when the encoded output needs to be typed by humans without case-sensitivity confusion.

The decoder validates each character against the Base32 alphabet. If an invalid character is found, it shows a clear error message. Whitespace and the = padding character are handled correctly during decoding.