What are QR Codes?  screenshot

What are QR Codes?

QR (Quick Response) codes, as well as the everyday barcode are used to encode characters in such a way that they can be quickly read by a special reader. A QR Code, contrary to the barcode is two-dimensional and the data carrier is not the mark, but the square of dark and light modules. They are the equivalent of ones and zeros that can be used to encode any character. Therefore with QR Codes, you can store both numeric characters (like barcodes do) and the alphanumeric Arabic alphabet, Greek, Hebrew, Japanese and Cyrillic.

Originally invented for industry and transportation, QR Codes could mark a shipment so that it could be quickly recognized and addressed to the appropriate place for sorting. Currently they are also applied to everyday life, you just need a computer with a webcam or a phone with a built-in camera and an appropriate application to decipher the contents of a tangle of black and white squares in a fraction of a second. QR Codes are most commonly used in advertising and newspapers, because with their help you can easily send users a complicated web address. You can see how easy they are to use just by following the information text that accompanies the QR Code.

How are QR Codes constructed?

QR Code always have a form of a square filled with dark and bright spots (so-called modules). Inside are encoded characters, accompanied by the information you need to enable reading the code (see infographic below).

The number of modules in the code determines the amount of information that can be saved. The smallest QR Code (version 1) has a size of 21x21 modules. Subsequent versions have changed the length of the sides of the four modules. The largest QR Code (version 40) has a size of 177x177 modules.

In the chaos of lines and angles in the QR Code, you can save quite a bit of information. The data is encoded both vertically and horizontally. Version 40 QR Codes can contain an over 4000 alphanumeric characters, which are letters, numbers and special characters.

What is required to read QR Codes?

You need a mobile phone , computer, laptop or tablet with a camera. It is necessary to have the right application. Use the appropriate store for your system (for example, App Store or Android Market) to find a smartphone application, by typing QR in the search box.

How to create QR Codes

It's pretty simple to create a QR Code. Using QR Codes do not require any license, so anyone can create and use them for free. The essential element is a suitable generator. On the Internet you can easily find free online generators. At the end of the article we will show how to use one of these tools called the GoQR generator. Some other generators to try are available at and QRCode . You could also try the phone app QR Droid or the androidowy program.

Since the QR Code can be saved as a graphic file (JPG, PNG, GIF or TIFF), you can do almost anything with it - print with an inkjet or laser printer, put on your own web page, send it as an email, print it on to a t-shirt or mug or set it as a screen saver.

What size should a QR Code be?

In principle, size is not a restriction. It is only important that it has a readable code. For example, a huge code on a wall or billboard can be read at a great distance.

If the code is too small, however, it can be difficult for some phones with poor quality digital camera. Therefore, even if the QR Code contains only one Internet address should be at least the size of 2,5x2,5 centimeter. Of course, the code contains more information, its individual modules are smaller. So in order to read it did not cause trouble, the image size of the code should be larger.

Less well known 2D codes

Although QR Codes are now the most popular and you can save them the most characters (even more than 4000), sometimes used are also other two-dimensional codes.

How do you generate code? We have a quick tutorial for you

On the internet you will find several free QR Code generators. One of the easiest to use is GOQR.ME. Let's see how to use it.


Open the GoQR site . The QR Code generator appears in the default text format (change the format by clicking on one of the tabs). To generate a QR Code with text, type it in to the box. Momentarily, your QR Code will be ready.


Using the slider, you can change its size (move the slider to the right). Finally, to download a picture of the code to the hard just press the button and you will get your own QR code.