baseX-converter

Due to the limitation of JavaScript's integer representation, which is limited to 53 bits, handling large numbers for encryption tasks can be challenging. Existing libraries run into problems when dealing with such values;
To fix this limitation, This library provides encoding of large numbers. This library provides the following features:

Encoding and decoding of various data types:

• Regular numerical values
• Hexadecimal values
• Binary data as Uint8Array Base Conversion: This library provides a multipurpose convert_base() function that can convert a value from any base to another base without rounding off and size restriction

By overcoming JavaScript's integer limitations, this library allows developers to efficiently work with large numbers in encoding and base conversion tasks.

[!CAUTION] Be careful, spaces(" ") in the whole value and zeros(0) at the beginning of the value being ignored

---

Default alphabet: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
Inverted alphabet: "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
Default base: 62

Alphabets

See below for a list of commonly recognized alphabets, and their respective base.

Base	Import Name	Alphabet
2	ALPHABET_BASE2	01
8	ALPHABET_BASE8	01234567
11	ALPHABET_BASE11	0123456789a
16	ALPHABET_BASE16	0123456789abcdef
32	ALPHABET_BASE32	0123456789ABCDEFGHJKMNPQRSTVWXYZ
36	ALPHABET_BASE36	0123456789abcdefghijklmnopqrstuvwxyz
58	ALPHABET_BASE58	123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz
62	ALPHABET_BASE62_Default	0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
64	ALPHABET_BASE64	ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
67	ALPHABET_BASE67	ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.!~

Getting started

Installation

npm install base-62

Alternatively using Yarn:

yarn add base-62

Usage

---

Import

import base62 from 'base62';
// or for making instance with custom alphabet
import {Base62, ALPHABET_BASE62_Default, ALPHABET_BASE62_INVERTED, BASE_DEFAULT} from 'base62';

Commonjs require

const base62 = require('base62').default;
const {Base62, ALPHABET_BASE62_Default, ALPHABET_BASE62_INVERTED, BASE_DEFAULT} = require('base62');

base62.decode('base62');
// '34441886726'
base62.encode('34441886726');
// 'base62'

Encode and decode bytes

base62.encode_bytes(new Uint8Array([0x01, 0x01]));
// '49'
base62.decode_bytes('49');
// Uint8Array(2) [ 1, 1 ]

Encode and decode hex

This function is useful to encode and decode MongoDB ObjectId too

base62.encode_hex('604a38563');
// 'sdg16r'
base62.decode_hex('sdg16r');
// '604a38563'

// encode and decode mongodb objectid
base62.encode_hex('63d91de18f092ab964484b9e');
// 'eBhQNIyMqR6WH3XS'
base62.decode_hex('eBhQNIyMqR6WH3XS');
// '63d91de18f092ab964484b9e'

Base converter

This function is able to convert any base to another with no limit on the size of value

base62.convert_base('ff', 16, 10);
// '255'
base62.convert_base('wiv', 36, 10);
// '42151'
base62.convert_base('123456789123456789123456789123456789123456789', 10, 16);
// '58936e53d139afefabb2683f150b684045f15'

This library provides the ability to change the alphabet and base for encoding and decoding. However, changing the base is not recommended unless you are sure that the chosen base works without malfunctioning.
But the alphabet can be changed without functional problems. it just sensitive to "space" character, and we can not use it.

import base62, {
    ALPHABET_BASE58,
    ALPHABET_BASE62_INVERTED,
} from 'base62';
// make instance
const base62 = new Base62();
// make another base
const base62 = new Base62(ALPHABET_BASE58, 58);
;
// or you can set alphabet
const base62 = new Base62('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz');
// or base
const base62 = new Base62('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz', 62);

Can pass custom alphabet for each converting

base62.decode('base62', '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz');
// '34441886726'
base62.encode('34441886726', '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz');
// 'base62'

Change alphabet or base, for changing base you should set a compatible alphabet too

import base62, {
    ALPHABET_BASE58,
    ALPHABET_BASE62_INVERTED,
} from 'base62';
// use costom alphabet
base62.setAlphabet('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz');
// or use existing ones
base62.setAlphabet(ALPHABET_BASE62_INVERTED);
base62.setBaseAlphabet(ALPHABET_BASE58, 58);