Base32 Encoder Decoder

Base32 is a binary-to-text encoding scheme defined in RFC 4648 that converts binary data into a printable ASCII string format. It uses 32 characters (A-Z and 2-7) to represent binary data in a human-readable way. Base32 encoding is commonly used for TOTP secrets, DNSSEC records, hash visualization, and other applications where a case-insensitive alphanumeric encoding is preferred.

The term "Base32" comes from the fact that the encoding uses a base-32 numeral system to represent 5 bits of data using each character. Every 5 bytes (40 bits) of input are encoded into 8 Base32 characters (each representing 5 bits). This means that Base32-encoded data is approximately 60% larger than the original binary data (compared to Base64's 33% overhead).

Base32 encoding works by taking the binary representation of the input data and grouping it into 5-bit chunks. Each 5-bit chunk is then converted to its corresponding Base32 character. If the input data is not a multiple of 5 bytes, padding characters (=) are added to make the output length a multiple of 8 characters.

When Should You Use Base32 Encoding?

• TOTP Secrets — Google Authenticator and other 2FA apps use Base32-encoded secrets (RFC 6238)
• DNSSEC Records — DNS security extensions use Base32 for NSEC record hashes (RFC 5155)
• Hash Visualization — SSH key fingerprints and OpenPGP keys use Base32 for human-readable identification
• Case-Insensitive Data — When encoding needs to be case-insensitive (Base32 uses only uppercase letters)
• Human Transcription — When codes need to be read aloud or transcribed manually without confusion between similar characters

Base32 vs. Base64

While Base64 is more space-efficient (33% overhead vs 60% for Base32), Base32 offers advantages in specific scenarios:

• Case insensitivity — Base32 uses only uppercase letters, making it suitable for voice transcription
• No ambiguous characters — Doesn't use 0, 1, 8, 9, +, or / that can be confused
• URL-safe by default — The Base32 alphabet contains no characters with special meaning in URLs
• Standard for 2FA — Required for compatibility with Google Authenticator and most TOTP apps

1. Choose your mode — Click the toggle switch to select Encode (text → Base32) or Decode (Base32 → text).
2. Enter your data — Type or paste text directly into the input area.
3. Submit — Click the Encode or Decode button to process your data.
4. Copy the result — Use the copy button in the result panel to copy the output to your clipboard instantly.