⚡ 5 Base32 Variants Supported

Base32 Encoder Online

Encode plain text, hexadecimal, binary, and 2FA secrets into Base32 formats (RFC 4648, Base32Hex, Crockford, z-base-32, Geohash) with padding controls and 100% browser privacy.

How to Use the Base32 Encoder

1

Select Input Mode

Choose Plain Text (UTF-8), Hexadecimal, Binary Bits, or 2FA Secret Generator.

2

Choose Base32 Variant

Select RFC 4648 Standard (A-Z, 2-7), Base32Hex, Crockford Base32, z-base-32, or Geohash.

3

Configure Output

Toggle padding (=), switch UPPERCASE/lowercase, or add Crockford Modulo 37 Checksum.

4

Review & Copy

Inspect the Bit Breakdown Matrix, compare cross-variant outputs, and copy or download the encoded string.

Understanding Base32 Encoding, Specifications, & Cryptographic Use Cases

Base32 is a binary-to-text encoding scheme defined in RFC 4648 designed to represent arbitrary binary data using a 32-character ASCII subset. Unlike Base64, which relies on a case-sensitive 64-character alphabet, Base32 uses a smaller, case-insensitive alphabet that eliminates ambiguous characters, making it the industry standard for two-factor authentication (2FA) secrets, human transcription, DNSSEC, and file systems with case-insensitive constraints.

How Base32 Bit Chunking Works (8-Bit Bytes to 5-Bit Chunks)

In Base32, input data is processed in 40-bit blocks (the Least Common Multiple of 8-bit bytes and 5-bit Base32 symbols):

  • Every 5 input bytes (40 bits) maps exactly to 8 Base32 output characters.
  • If the input byte length is not a multiple of 5, the remaining bits are zero-padded on the right, and trailing = padding characters align the final string to a multiple of 8 characters.
  • Theoretical byte expansion ratio: 1.6x.

Comparison of Major Base32 Alphabets & Specifications

SpecificationAlphabet CharactersPaddingPrimary Use Cases
RFC 4648 StandardA–Z, 2–7Mandatory =TOTP / HOTP 2FA Secrets (RFC 6238), Tor v3 onion
RFC 4648 Base32Hex0–9, A–VMandatory =DNSSEC NSEC3 records, database indexing
Crockford Base320–9, A–Z (excl. I, O, L, U)None (Mod 37 Checksum)ULID, human serial numbers, license keys
z-base-32ybndrfg8ejkmcpqx...NoneTahoe-LAFS, human-transcribed tokens

100% Privacy & Security Guarantee

Authentication credentials and TOTP secret keys must never be transmitted over the internet to remote servers. Our Base32 Encoder executes 100% inside your browser using Web Workers and modern JavaScript APIs. Zero data is uploaded or logged to any server.

Frequently Asked Questions

What is Base32 encoding?

Base32 is a binary-to-text encoding scheme defined in RFC 4648 that represents data using a 32-character alphabet (such as A-Z and 2-7). Each character encodes exactly 5 bits of binary data.

Where is Base32 commonly used?

Base32 is widely used in TOTP/HOTP 2FA authentication secret keys (Google Authenticator, Authy, Bitwarden), Tor v3 onion addresses, DNSSEC records, and case-insensitive file systems.

What is the difference between Base32 and Base64?

Base32 uses 5 bits per character (32-character alphabet) and is case-insensitive, making it human-transcribable. Base64 uses 6 bits per character (64-character alphabet) and is case-sensitive, making Base64 ~20% more compact than Base32.

What Base32 variants are supported?

We support 5 variants: RFC 4648 Standard (A-Z, 2-7), RFC 4648 Base32Hex (0-9, A-V), Crockford’s Base32 (excludes I, O, L, U with optional Modulo 37 Checksum), z-base-32 (human-readable), and Geohash Base32.

Why do 2FA secret keys use unpadded Base32?

Many authenticator apps (like Google Authenticator) expect Base32 secrets without trailing "=" padding characters. Our tool lets you toggle padding on or off with a single click.

How does Crockford’s Base32 work?

Crockford’s Base32 eliminates visually ambiguous characters (I, L, O) and excludes U to prevent accidental profanity. It supports an optional Modulo 37 Checksum symbol for error-detection in human entry.

Can I encode Hexadecimal or Binary input directly?

Yes! Switch input tabs to Hexadecimal (e.g. 48656c6c6f) or Binary Bits (0s and 1s) to encode raw byte streams into Base32.

Is my input uploaded to any server?

No. 100% of encoding, bit manipulation, and 2FA secret generation executes locally in your browser using JavaScript Web Workers. Zero data leaves your machine.

What is the theoretical byte expansion ratio of Base32?

Base32 expands binary data by approximately 1.6x (8 characters per 5 bytes of binary data, plus any necessary "=" padding characters).

Can I generate a random 2FA TOTP secret key?

Yes. Switch to the "2FA Secret Generator" tab to create cryptographically random 16, 26, or 32-character Base32 secret keys for two-factor authentication.

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