DEV Community

Cover image for WHY DO QR CODES HAVE 3 BIG SQUARES?
Pooja Sanap
Pooja Sanap

Posted on

WHY DO QR CODES HAVE 3 BIG SQUARES?

Almost all of us have seen QR codes before, they are like everywhere now, from making payments, or packaging gadgets or on business cards. Companies and even people nowadays use QR code to give information that is quickly accessible and can be seen even with a smartphone. But have you ever wondered why there are 3 big squares in each and every QR code we have come across.

First, let's take a look at what are these QR's actually?

So, basically, the term QR stands for Quick Response Code. QR codes are square barcodes (two-dimensional barcodes) that were first developed and used in Japan. Like any other barcode, a QR code is nothing more than a way to store information in a machine-readable optical label. The data contained by a QR code can be anything from simple text to email addresses, phone numbers, and so on.

QR codes store data using patterns of black dots and white spaces arranged in a square grid. These patterns can be scanned and translated into human-readable information, with the help of an imaging device, like a camera or a scanner.

But why these 3 big squares?

We can do an experiment to understand this:

Attached below is a reference key. You don't have to remember it, you can always look at it any time you need.

Image description

Now, I want you to compare the below character to the key and identify it.

Image description

Well, that was pretty easy! Yes, you got it right !! It's number 5. (Even if you didn't find, there is nothing to be worried about, you can crosscheck now.)

Now, I want you to try this:

Image description

It's not that easy anymore, isn't it?
But now check the image below.

Image description

You can clearly see when the QR code has the squares, the smartphone or any scanning device and quickly figure out a way to rotate and resize the code, turning it to this(below image).

Image description

And now you can guess it, right?
Yes, absolutely, it's number 3.
This is why there are these 3 big squares.
They ensure the codes can be correctly read.

Hope you read something interesting and informative!

Follow for more much informative content.
Share your thoughts and suggestions if any.

Discussion (0)