QR codes have been appearing everywhere recently and although not something new, they have been quietly creeping into posters, newspapers, namecards, and even in restaurant menus. If you are wondering what these pixellated squares are and how to use them, this guide will take you through the basics of a QR code, examples of these codes, the tools and apps available for you to scan these codes, what QR codes are used for, how to make one yourself, and some interesting uses of QR codes.

QR Codes For Dummies
Amazon Price: $9.99 $4.66 Buy Now
(price as of Apr 6, 2016)
Don't be misled by the For Dummies title, this book about QR Codes is comprehensive and does not just introduce the basics. You will also find out how to use QR codes with your business, how to plan QR code campaigns, how to track them and much more.

What is a QR code

Before you learn how to use QR codes, it would probably be good to know what it actually is. QR codes are a type of bar code that were first created in Japan. QR codes are also called other names such as Quick Response (hence the QR) Code and Denso Code (they were created by the company, Denso Wave). You can store all kinds of text information in a QR code, including numbers, alphabets, symbols, and kanij characters.

QR codes vary in size and in general, larger and denser QR codes can store more information. The maximum amount of information stored in a QR code is 1852 characters.

Examples of different QR codes

Here's a large QR code with a paragraph from Alice in Wonderland:

Large QR codeCredit: Generated with http://www.racoindustries.com/barcodegenerator/2d/qr-code.aspx

And here's what you'll get in the QR code scanner or reader. That wasn't the complete text that was stored in the QR code because my screen wasn't large enough. There were a total of 280 words and 1571 characters in it. You can scan it for yourself and see.

QR code scanned - Alice in Wonderland

Of course that was properly larger than what you'll normally see, so here's a more common and smaller QR code.

example qr codeCredit: http://en.wikipedia.org/wiki/File:Qr-3.svg

How to use QR codes

Using a QR code is relatively simple. All you need is a QR code reader or scanner which you can download as an app for your iOs, Android or BlackBerry phones. Some devices such as the Nintendo 3DS also have a built-in function to scan the codes with its camera.

If you don't already have the apps, here's a good one you can get for the iOs or Android.

QR Reader for iPhone by Tap Media Ltd[4] (or just QR Reader on Android)[3]

This free QR code scanner auto detects the QR code (no need to press a button to scan it, just hold it over the code). When scanning a URL, you will automatically go to the page but there is also a QR lock function that lets you approve the website before going to it. I like this feature because many QR code scanners just open a web page when scanning a code with a URL without allowing you to check what you are scanning. Although there aren't many people making spam codes right now, I think this feature will come in handy when the spammers start catching on to it.

You can share your codes on social media such as Facebook or Twitter. The app also lets you create QR codes with URL, text, phone numbers, e-mail, GEO location and so on. You can even make URLs that link to your social media profiles by just entering your username.

This app is ad-supported with an option to remove the advertisement for a fee.

If you need a code with an URL to try, scan the one below for this article's URL:

QR code with InfoBarrel URL

You can also read QR codes in your browser with the Chrome extension QRreader beta.

How to create QR codes

You don't need an app to make a QR code. There are many web sites that allow you to make these codes for free and some even let you customize them with better graphics and features. Here are some of the ones I like best:

The Unitag QR code maker[5] is an awesome web site that lets you create highly customized QR codes with different colors, shapes, and you can even add in your own logo. Here's one I made with it that points to this page.

InfoBarrel QR code

An important note: Although QR codes are quite customizable, if you change the way it looks too much, it may not be readable or scannable. Always scan your code to check if it's readable before you use it or send it to anyone else.

If logos are not your thing and you just want a quick QR code with color (or black), you can try QR Stuff[6]

A useful chrome extension that lets you generate QR codes of pages that you are currently browsing is the QR-Code Tag. It lets you right click pages and generate a QR code for the URL. The code can then be easily shared on Facebook, Twitter, or saved to your computer. 

Interesting uses of QR codes

Here are some examples that may give you some ideas on how to use QR codes.

QR Codes in mobile or virtual shopping

QR codes have been used in mobile shopping where users can buy stuff by scanning codes displayed at various places such as train stations. Commuters can do their grocery shopping with the time that's usually wasted on traveling from one place to another, and have their grocery delivered to them.

Describing it with a chunk of text does this no justice. Look at the video below to see what can be done.

Example of a QR code virtual store

QR codes for meet-ups

The Japanese app Phewtick generates QR codes unique to a user's mobile and lets users scan QR codes from friends and other people to earn points. Although not implemented at the moment, Phewtick has plans to collaborate with retailers and merchants for location-based promotions that target nearby Phewtick users.

QR codes for newspapers

I noticed this the other day -- the Straits Times newspaper has been using QR codes that link to a related video on some of the news articles that they print. I guess there's hope for the print media after all.

Newspaper QR code