Coupon Code Generator

Generate unique, hard to guess coupon, voucher codes.

Use cases: promo codes, loyalty coupons, gift vouchers, in-app purchases

This library originates from Voucherify.

Installation

In Node.js

Install with npm:

$ npm install --save voucher-code-generator

Include with require:

var voucher_codes = require('voucher-code-generator');

In a browser

<script src="voucher_codes.js"></script>

Usage

Generate 5 codes, each 8 characters long:

voucher_codes.generate({
    length: 8,
    count: 5
});

Sample result: ["FR6bwx1q", "ByamOdWV", "7roFwfQs", "rmWlwvll", "pgih5eAB"]

Charset

Default charset is alphanumeric (numbers and letters). However, you can specify your own charset:

voucher_codes.generate({
    length: 6,
    count: 3,
    charset: "0123456789"
});

Sample result: ["386525", "676442", "019075"]

You can also use one of the predefined charsets by calling voucher_codes.charset(name).

name	charset
"numbers"	"0123456789"
"alphabetic"	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
"alphanumeric"	"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

For example:

voucher_codes.generate({
    length: 5,
    count: 4,
    charset: voucher_codes.charset("alphabetic")
});

Result: ["odghy", "kZEYc", "eOTCl", "wVCzD"]

Prefix and Postfix

You can optionally surround each generated code with a prefix and/or postfix.

For instance:

voucher_codes.generate({
    prefix: "promo-",
    postfix: "-2015"
});

Result: ["promo-WZ4x1t3U-2015"]

Pattern

Codes may follow a specified pattern. Use hash (#) as a placeholder for random characters. Notice that if pattern is specified then length is ignored.

Example:

voucher_codes.generate({
    pattern: "##-###-##",
});

Result: ["P7-ofW-Ka"]

Infeasible configs

There exist some configs that are not feasible. For example it's not possible to generate 1000 codes if you want your codes to be 2 characters long and consisting only of numbers. Voucher code generator detects such cases and throws an error "Not possible to generate requested number of codes.".

try {
    voucher_codes.generate({
        count: 1000,
        length: 2,
        charset: "0123456789"
    })
catch (e) {
    console.log("Sorry, not possible.");
}

Config reference

attribute	default value	description
length	8	Number of characters in a generated code (excluding prefix and postfix)
count	1	Number of codes generated.
charset	alphanumeric	Characters that can appear in the code.
prefix	""	A text appended before the code.
postfix	""	A text appended after the code.
pattern	"########"	A pattern for codes where hashes (#) will be replaced with random characters.

Testing

Install dependencies:

npm install

Run tests:

npm run test

License

Code released under the MIT license.