base32kit

Tiny, isomorphic Base32 codec — RFC 4648, base32hex, and Crockford, between strings and Uint8Array. Zero dependencies.

Buffer doesn't do Base32, and you reach for it when handling TOTP/2FA secrets (RFC 4648) or Crockford ids. base32kit covers all three common alphabets, both directions, between strings and bytes — the same in Node and the browser. Zero dependencies. (For Base64/hex, see its sibling codeckit.)

import { encode, decode } from "base32kit";

encode("foobar");                 // "MZXW6YTBOI======"
decode("MZXW6YTBOI======");       // "foobar"
encode("id", { variant: "crockford" }); // unpadded Crockford

Why base32kit?

• Three alphabets. rfc4648 (default, A–Z2–7), hex (base32hex, 0–9A–V), and crockford (0–9A–Z minus I L O U, case-insensitive, no padding).
• Tolerant decoding. Case-insensitive, ignores padding, whitespace, and -; Crockford also accepts O→0 and I/L→1.
• RFC-correct. Passes the RFC 4648 §10 test vectors exactly.
• Bytes or text. Low-level Uint8Array functions plus UTF-8 text wrappers.
• Isomorphic & tiny. Node, Deno, Bun, browsers. Full types, ESM + CJS, zero dependencies.

Install

npm install base32kit
# or: pnpm add base32kit  /  yarn add base32kit  /  bun add base32kit

Text

import { encode, decode } from "base32kit";

encode("foobar");                          // "MZXW6YTBOI======"
encode("foobar", { pad: false });          // "MZXW6YTBOI"
encode("foo", { variant: "hex" });         // "CPNMU==="
decode("mzxw6ytboi", { variant: "rfc4648" }); // "foobar" (case + padding tolerant)

Bytes

import { bytesToBase32, base32ToBytes } from "base32kit";

bytesToBase32(new Uint8Array([1, 2, 3, 4, 5]));                 // RFC 4648
bytesToBase32(secret, { variant: "crockford" });               // unpadded
base32ToBytes("JBSWY3DPEHPK3PXP");                             // → Uint8Array

// TOTP secret → bytes
const key = base32ToBytes(otpSecret.replace(/\s/g, ""));

interface EncodeOptions {
  variant?: "rfc4648" | "hex" | "crockford"; // default "rfc4648"
  pad?: boolean; // default: on for rfc4648/hex, off for crockford
}

Contributors ✨

This project follows the all-contributors specification. Contributions of any kind are welcome — code, docs, bug reports, ideas, reviews! See the emoji key for how each contribution is recognized, and open a PR or issue to get involved.

Thanks goes to these wonderful people:

License

MIT © Tung Tran