QR Code Encoder

A lightweight library generating stylish QR codes that also support gradient fills and rounded corners in only 12.2kB minified (4.75kB gzipped). Try out the demo!

Origin

This library is a trimmed down version of Lars Jung's jQuery.qrcode library. Our library is however not based on jQuery anymore and doesnt make use of it. Lars Jung's library itself is based on this QR code Generator.

All parts are licensed under the MIT License.

Installation

To install via npm:

npm install --save qr-creator

To install via yarn:

yarn add qr-creator

Or use a cdn like jsdelivr or unpkg (see usage).

Usage

The library is available as a module and non-module version. To import it as a module:

  // from installed package for bundling with a module bundler like webpack:
  import QrCreator from 'qr-creator';
  // from cdn:
  import QrCreator from 'https://cdn.jsdelivr.net/npm/qr-creator/dist/qr-creator.es6.min.js';

To use the non-module version:

  <!-- from your project's code base -->
  <script src="path/to/qr-creator.min.js"></script>
  <!-- from cdn -->
  <script src="https://cdn.jsdelivr.net/npm/qr-creator/dist/qr-creator.min.js"></script>

Call the QrCreator API with a configuration object and a DOM element or canvas to render the QR code into:

  QrCreator.render({
    text: 'some text',
    radius: 0.5, // 0.0 to 0.5
    ecLevel: 'H', // L, M, Q, H
    fill: '#536DFE', // foreground color
    background: null, // color or null for transparent
    size: 128 // in pixels
  }, document.querySelector('#qr-code'));

Attribute	Options	Default	Description
text	String	""	Any kind of text, also links, email addresses, any thing. The library will figure out the size of the QR code to fit all the text inside.
radius	0 .. 0.5	0.5	Defines how round the blocks should be. Numbers from 0 (squares) to 0.5 (maximum round) are supported.
ecLevel	L, M, Q, H	L	Means "Error correction levels". The four values L, M, Q, and H will use %7, 15%, 25%, and 30% of the QR code for error correction respectively. So on one hand the code will get bigger but chances are also higher that it will be read without errors later on.
fill	color or gradient	#000000	What color you want your QR code to be. Use the demo to try different colors.
background	color code	null	The background color or null for transparent background.
size	int	200	The total size of the final QR code in pixels - it will be a square.

If you want to fill the QR code with a gradient, use the following format:

{
    type: 'radial-gradient', // or 'linear-gradient'
    position: [ ... ],
    colorStops: [
        [ offset0, color0 ],
        [ offset1, color1 ],
        ...
    ]
}

Where the position is specified as in createLinearGradient / createRadialGradient. However, each value is relative to the QR code size, i.e. will be multiplied by that size to yield the absolute position.

Trimmed down to be low weight

The goal of the library is to generate QR codes only. For that reason we have removed all additional code such as GIF image generation, background image support, rendering a label on top, removed some dead code, and freed it from depending on jQuery. Also, the resulting library does not use any global variables, is all strict mode, and relies on modern browser standards instead.

The result	Original	New
Lines of code	2332	1556 (-33%)
Size	64kB	50kB (-22%)
Minified	20.6kB	11.95kB (-40%)
Gzipped	7.3kB	4.77kB (-35%)

Building

To install the dependencies run:

npm install

and then to build the project:

npm run build