TypeScript | Base73

An ASCII encoding scheme with a base of 73 for binary data.

Base73 is an encoding scheme for binary data using a base of 73 and an ASCII character set. Binary data is taken 7 bits at a time, and mapped to each character. Since 2^7 is equal to 128, the first 54 characters of the set contain secondary values, which are represented by prefixing the character with the secondary access character. The secondary access character is ^ (ASCII 94).

Natively in TypeScript, with ESM and CommonJS compatibility. To get started, install the library:

# Deno
deno add jsr:@jacobhaap/base73

# Node.js
npm install base73

Character Set:

!#$%&+-0123456789<>@ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz

Encoding

A Uint8Array can be encoded to a base73 string using the encode function.

The encode function has one input parameter:

function encode(bytes) {};

Where:

• bytes is binary data for encoding.

The bytes parameter is expected as a Uint8Array. The encode function is synchronous, and returns a string.

Example use:

import { encode } from "@jacobhaap/base73";

const bytes = Uint8Array.from([34, 84, 104, 101, 32, 71, 97, 109, 101, 34]);
const str = encode(bytes); // <B6-V#7^Eh^9QM

Decoding

A base73 string can be decoded to a Uint8Array using the decode function.

The decode function has two input parameters:

function decode(str, strict = true) {};

Where:

• str is a base73-encoded string for decoding.
• strict is an optional value to disable strict decoding.

The str parameter expects a base73- encoded string, and the optional strict parameter expects a boolean value (defaults to true). The decode function is synchronous, and returns a Uint8Array.

Example use:

import { decode } from "@jacobhaap/base73";

const str = "<B6-V#7^Eh^9QM";
const bytes = decode(str);

/*
Uint8Array(10) [
  34, 84, 104, 101, 32,
  71, 97, 109, 101, 34
]
*/