codeckit

Tiny, isomorphic Base64 / Base64URL / hex codec — strings and Uint8Array, Node and browser, no Buffer. Zero dependencies.

Buffer doesn't exist in the browser, and btoa/atob choke on Unicode and binary data. codeckit does Base64, Base64URL, and hex the same way everywhere — between strings and Uint8Array — with byte-for-byte output matching Node's Buffer. Zero dependencies, tree-shakeable.

import { base64Encode, base64Decode } from "codeckit";

base64Encode("héllo 😀");        // "aMOpbGxvIPCfmIA="  (UTF-8 safe)
base64Decode("aMOpbGxvIPCfmIA="); // "héllo 😀"

Why codeckit?

• Isomorphic. Identical results in Node, Deno, Bun, and browsers — no Buffer, no btoa.
• Unicode-safe. Strings are encoded as UTF-8, so emoji and accents survive (btoa("😀") throws — this doesn't).
• Base64URL built in. { url: true } for -/_, { pad: false } to drop = — exactly what JWTs and URLs want.
• Bytes or text. Low-level Uint8Array ↔ string functions, plus text convenience wrappers.
• Correct & verified. Output matches Node's Buffer byte-for-byte across the test suite.
• Zero dependencies, ESM + CJS + types, tree-shakeable.

Install

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

Text helpers

import { base64Encode, base64Decode, hexEncode, hexDecode } from "codeckit";

base64Encode("hello");                       // "aGVsbG8="
base64Encode("data", { url: true, pad: false }); // URL-safe, unpadded
base64Decode("aGVsbG8=");                     // "hello"

hexEncode("hi");                              // "6869"
hexDecode("6869");                            // "hi"

Bytes

import {
  bytesToBase64, base64ToBytes,
  bytesToHex, hexToBytes,
  utf8Encode, utf8Decode,
} from "codeckit";

bytesToBase64(new Uint8Array([1, 2, 3]));      // "AQID"
base64ToBytes("AQID");                         // Uint8Array [1, 2, 3]

bytesToHex(new Uint8Array([255, 16, 0]));      // "ff1000"
hexToBytes("0xDEAD");                          // Uint8Array [222, 173]

utf8Encode("héllo");                           // Uint8Array (UTF-8)
utf8Decode(bytes);                             // string

base64ToBytes accepts standard or URL-safe input, padded or not, and skips whitespace. hexToBytes is case-insensitive and tolerates a 0x prefix and spaces.

interface Base64Options {
  url?: boolean; // -/_ alphabet (default false)
  pad?: boolean; // emit = padding (default true)
}

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