A simple QR Code generator in pure JavaScript

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428241.1.05 years ago8 years agoMinified + gzip package size for qrcode-svg in KB



This library has been written to generate a SVG image of QR Code in Node.js, goals:
  • pure JavaScript
  • no browser requirement
  • no external dependencies
  • generate SVG output

Getting Started

Install the package: ```bash npm install qrcode-svg ``` Inline example: ```javascript var QRCode = require("qrcode-svg"); var svg = new QRCode("Hello World!").svg(); ``` More options: ```javascript var qrcode = new QRCode({ content: "http://github.com/", padding: 4, width: 256, height: 256, color: "#000000", background: "#ffffff", ecl: "M", }); qrcode.save("sample.svg", function(error) { if (error) throw error; console.log("Done!"); }); ```


List of options:
  • content - QR Code content, the only required parameter
  • padding - white space padding, 4 modules by default, 0 for no border
  • width - QR Code width in pixels
  • height - QR Code height in pixels
  • color - color of modules (squares), color name or hex string, e.g. #000000
  • background - color of background, color name or hex string, e.g. white
  • ecl - error correction level: L, M, H, Q
  • join - join modules (squares) into one shape, into the SVG path element, recommended for web and responsive use, default: false
  • predefined - to create a squares as pattern, then populate the canvas, default: false, see the output examples below
  • pretty - apply indents and new lines, default: true
  • swap - swap X and Y modules, only if you have issues with some QR readers, default: false
  • xmlDeclaration - prepend XML declaration to the SVG document, i.e. <?xml version="1.0" standalone="yes"?>, default: true
  • container - wrapping element, default: svg, see below
Container options:
  • svg - populate squares in a SVG document with width and height attriute, recommended for converting to raster images or PDF where QR Code is being static (exact size)
  • svg-viewbox - populate squares in a SVG document with viewBox attriute, recommended for responsive web pages
  • g - put squares in g element, useful when you need to put multiple QR Codes in a single SVG document
  • none - no wrapper

SVG output

Editable squares

This mode is useful for designers to manipulate with particular squares. Thus, one can open the QR Code in an editor, select particular modules, move around, change color, etc. However, some old SVG viewers may generate minor gaps between the squares - the side effect when rendering an image at certain zoom level. Default options ```javascript var qrcode = new QRCode({ content: "Pretty Fox", join: false, predefined: false }); ``` Output with rect elements ```xml ... ```

Responsive web page

Squares joined into one path shape produce a compact file size, i.e. 4-5x reduced compared with rect elements. A single path element will result in an optimized rendering, thus not producing any minor gaps between the squares. Also using the container with viewBox attribute may contribute to the responsive scaling on the web. Set join to true ```javascript var qrcode = new QRCode({ content: "Pretty Fox", join: true, container: "svg-viewbox" //Useful but not required }); ``` Output with path element ```xml ```

Predefined pattern

Algorithm defines the square pattern once before populating a canvas. Useful if you want to generate QR Code with candies. However, some SVG software and converters do not support defs or use elements. Set predefined to true ```javascript var qrcode = new QRCode({ content: "Pretty Fox", predefined: true }); ``` Output with defs and use elements ```xml ... ```

Command Line

``` Usage: qrcode-svg options Options: --help Print this message --version, -v Print version number --padding , -p value Offset in number of modules --width, -w px Image width in pixels --height, -h px Image height in pixels --color, -fg color Foreground color, hex or name --background color Background color, hex or name --ecl value Error correction level: L, M, H, Q --join Join modules into one SVG path, i.e. for crisp rendering --predefined Use 'defs' and 'use' elements in SVG, i.e. for compact output --no-prettify Avoid indenting and new lines in SVG, i.e. for compact output --viewbox Use 'viewBox' instead of 'width' and 'height' attributes --swap-fix Swap X and Y modules to fix issues with some QR readers --output, -o file Output file name --force, -f Force overwrite Examples: qrcode-svg http://github.com qrcode-svg -f -o hello.svg "Hello World" qrcode-svg -p 4 -w 256 -h 256 --join --viewbox "Responsive..." qrcode-svg --padding 2 --width 120 --height 120 "Little fox..." qrcode-svg --color blue --background #ececec "...jumps over" ```

Usage Scenarios

Convert to other formats

Using html-pdf to convert SVG to PDF (or PNG or JPEG) ```javascript var QRCode = require('qrcode-svg'); var svg = new QRCode('hello').svg(); ... var pdf = require('html-pdf'); pdf.create(svg, { border: 0, type: 'pdf' }).toFile('output.pdf', function(err, res) { ... }); ```

ASCII modules

QR Code in ASCII to output in a shell ```javascript var QRCode = require('qrcode-svg'); var hello = new QRCode("Hello World!"); var modules = hello.qrcode.modules; var ascii = ''; var length = modules.length; for (var y = 0; y < length; y++) { for (var x = 0; x < length; x++) {
var module = modules[x][y];
ascii += (module ? 'x' : ' ');
} ascii += '\r\n'; } console.log(ascii); ``` ```
xxxxxxx xx    x x xxxxxxx
x     x  xxxx x x x     x
x xxx x xx  xx  x x xxx x
x xxx x       xx  x xxx x
x xxx x  x   x  x x xxx x
x     x  x  xx xx x     x
xxxxxxx x x x x x xxxxxxx
xx     xx        
x x  xx    x x   xx   x x
x x  xx x    xx x xx x
x  x xx   x x x  xx   xx
x xx  xxx xx x x  x  x x
xx  xxxx       xxxx    x
x x  x xx x xx xx x xx xx
x    xx   xxxx    xxxx   
xx xx   x  x  x x xx    x
xxxx xxxx    xxxxxx  x
x   x x  
xxxxxxx  x  xxx x x x   x
x     x xxx  x xx   x  x 
x xxx x        xxxxxxxxxx
x xxx x  xxxxxxxxx  x xx 
x xxx x xxx  xx  x    x x
x     x    x    x     x  
xxxxxxx xxx xxx   x   x x

Web browser

Use on a HTML page with JavaScript ```html


Thanks to davidshimjs for the base library. Thanks to Kazuhiko Arase for the original QR Code in JavaScript algorithm. Thanks to all contributors on the GitHub.

Legal notice

``` Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php The word "QR Code" is registered trademark of DENSO WAVE INCORPORATED http://www.denso-wave.com/qrcode/faqpatent-e.html ```