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A Ruby library that encodes QR Codes
branch: master

rQRCode, Encode QRCodes


rQRCode is a library for encoding QR Codes in Ruby. It has a simple interface with all the standard qrcode options. It was adapted from the Javascript library by Kazuhiko Arase.

Let's clear up some rQRCode stuff.

  • rQRCode is a standalone library It requires no other libraries. Just Ruby!
  • It is an encoding library. You can't decode QR codes with it.
  • The interface is simple and assumes you just want to encode a string into a QR code
  • QR code is trademarked by Denso Wave inc



You may get the latest stable version from Rubygems.

gem install rqrcode

You can also get the latest source from

git clone git://


To run the tests:

$ rake

Loading rQRCode Itself

You have installed the gem already, yeah?

require 'rubygems'
require 'rqrcode'

Simple QRCode generation to screen

qr = 'my string to generate', :size => 4, :level => :h )
puts qr.to_s
# Prints:
# xxxxxxx x  x x   x x  xx  xxxxxxx
# x     x  xxx  xxxxxx xxx  x     x
# x xxx x  xxxxx x       xx x xxx x
# ... etc

Simple QRCode generation to template (RubyOnRails)

# Controller
@qr = 'my string to generate', :size => 4, :level => :h )

# View: (minimal styling added)
<style type="text/css">
table {
  border-width: 0;
  border-style: none;
  border-color: #0000ff;
  border-collapse: collapse;
td {
  border-width: 0; 
  border-style: none;
  border-color: #0000ff; 
  border-collapse: collapse; 
  padding: 0; 
  margin: 0; 
  width: 10px; 
  height: 10px; 
} { background-color: #000; }
td.white { background-color: #fff; }

<% @qr.modules.each_index do |x| %>
  <% @qr.modules.each_index do |y| %>
   <% if @qr.dark?(x,y) %>
    <td class="black"/>
   <% else %>
    <td class="white"/>
   <% end %>
  <% end %>
<% end %>


Original author: Duncan Robertson

Special thanks to the following people for submitting patches:


  • Fork the project
  • Send a pull request
  • Don't touch the .gemspec, I'll do that when I release a new version


MIT Licence (

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