What is a QR Code and How Does It Work?

If you use apps like PhonePe, GooglePay, Paytm or BHIM UPI. So it is obvious that you must have known about QR Code . And would use it too! But do you know how QR code works? If not then nothing to worry. Because today we are going to talk about this. So let’s know what is the QR Code? How does this work? How is it generated? How is the scan done? And where is it used? Also, what information does it contain?

क्यूआर कोड परिभाषा और अर्थ

क्यूआर का अर्थ है “त्वरित प्रतिक्रिया।”

हालांकि वे सरल दिख सकते हैं, क्यूआर कोड बहुत सारे डेटा संग्रहीत करने में सक्षम हैं। लेकिन स्कैन किए जाने पर उनमें कितनी भी मात्रा क्यों न हो, क्यूआर कोड को उपयोगकर्ता को तुरंत जानकारी तक पहुंचने की अनुमति देनी चाहिए – इसलिए इसे त्वरित प्रतिक्रिया कोड क्यों कहा जाता है।

QR Code

QR code is the most widely used 2D barcode in the world. It is used in almost every shop, showroom, hospital, pub, restaurant, shopping mall etc. But in the last few years its trend has increased very rapidly. This is the reason why it is seen everywhere today. No matter what market you go to! You will see QR code everywhere from ration shop to fruit and vegetable stall.

क्यूआर कोड क्या है?

एक त्वरित प्रतिक्रिया कोड द्वि-आयामी बारकोड का एक लोकप्रिय प्रकार है । यह अल्फ़ान्यूमेरिक जानकारी को एन्कोड करता है। इसे डिकोड करने के लिए, आप या तो एक हैंडहेल्ड स्कैनर या यहां तक ​​कि अपने स्मार्टफोन पर एक क्यूआर कोड स्कैनिंग एप्लिकेशन का उपयोग कर सकते हैं।

वास्तव में, आईफोन, श्याओमी, मोटोरोला और सैमसंग जैसे कई स्मार्टफोन में अब उनके स्टॉक कैमरा एप्लिकेशन में इन-बिल्ट क्यूआर कोड स्कैनिंग फीचर है।

But this is not the complete picture. Actually QR code has become an integral part of our daily life. And most of us use it regularly in our day to day activities. But the question is what is this QR Code after all? And how does it work? Come on, let’s understand.

क्यूआर कोड कैसे काम करते हैं?

एक क्यूआर कोड एक स्कैन करने योग्य बारकोड है जो डेटा के साथ एन्कोड किया गया है। एन्कोडेड का अर्थ है किसी विशेष रूप में परिवर्तित । क्यूआर कोड के मामले में, संख्यात्मक और अल्फ़ान्यूमेरिक वर्ण, बाइट्स और कांजी वर्गों की एक अद्वितीय द्वि-आयामी व्यवस्था में परिवर्तित हो जाते हैं। जब एक ऑप्टिकल स्कैनर उन वर्गों के ऊपर से गुजरता है, तो यह उनकी व्यवस्था को उस डेटा के मूल रूप में वापस अनुवाद करता है।

यहाँ एक उदाहरण है। हम आतिथ्य व्यवसायों के लिए कस्टम, क्यूआर कोड-आधारित डिजिटल रेस्तरां टेबल मेनू बनाते हैं। इसलिए हमारे पास इच्छुक पार्टियों को दिखाने के लिए एक डेमो डिजिटल मेनू है। यह दिखाने के लिए कि हम क्या कर सकते हैं, हमने उस डेमो मेनू के यूआरएल को नीचे क्यूआर कोड में एन्कोड किया।

What is the QR Code?

A QR code is actually a two-dimensional barcode (2D barcode), which allows to store information (data) about a product. That is, it is a square grid, in which there are many pixels. And the data is stored in these Pixels. But it is machine readable . That is, it can only be read by the machine. That is why Imaging Devices such as Smartphone Camera, QR Code Reader or QR Code Scanner are used to read it.

I would like to tell you that the full form of QR Code is Quick Response Code . Which means quick responding code. That is, when it is scanned, it gives quick response. Due to which the scanning time takes very less. That is, QR code is such a barcode, which is known for quick response, fast readability and more storage.

On the other hand, if we talk about storing data, then QR code uses four encoding mods for this. i.e. Numerical, Alpha Numerical, Byte/Binary and Kanji (a variant of Chinese characters used in Japanese writing) modes. Usually it stores data as a series of Pixels.

How does QR Code work?

Now the question is how does QR code work? How does a QR Code work? So QR code actually works like a barcode. Only its texture is different. And in this instead of lines, Squares and Dots are used.
You must have noticed that QR code is a black colored square grid made on a white background. In which there are three small squares (at three corners). And there are many dots.

These points actually represent the data. That is, each point represents a certain piece of information . But this information is encoded in Numeric, Alphanumeric, Binary or Kanji form .

That is why it is read with the help of an imaging device (such as Smartphone, Camera etc.). And it is processed with the help of Reed-Solomon Code. That is, while fixing the errors, the correct information is reached. And after that data (information) is extracted from the pattern of Vertical and Horizontal Components . and translated as information that you and we can understand.

Types of QR Codes

There are mainly 2 types of QR codes. One, Static QR Code and the other, Dynamic QR Code. What’s the difference between the two? Come on, let’s understand. Types of QR Code .

1. Static QR Code

Static QR codes are static. They are not edited once generated. This means that the information contained in them cannot be changed. That’s why they are called Static QR Codes. They are used in such places, where there is no need to update the information. Such as advertisements published in newspapers, TV and magazines, posters, business cards, web URLs etc.

2. Dynamic QR Code

Dynamic QR codes are dynamic. This means that the information contained in them can be changed. And can be updated frequently. For example, if after generating the QR Code of a product, its price has to be changed! So can easily. That is, the new price is automatically updated in the QR code. And there is no need to print the QR code again.

QR Code के Variants

There are many variants (versions) of QR codes. Because over time there has been a lot of change in its design and specifications . And there have been many improvements. That is why today QR codes of different colors and designs are seen. But the question is what do these variants mean? Let’s know The Variants of QR Code :-

Model 1

This is the oldest and original QR code. It is also called Model 2 and prototype of Micro QR Code Because both these variants are extensions of Model 1. Although it looks similar to the Model 2 but it lacks the alignment pattern . The largest version of the Model 1 is 14 (73×73 modules), which can store a maximum of 1167 numerals.

Model 2

This is an improved version of Model 1 itself. And the word QR Code that you use today is used for this. It has alignment patterns , which help to read the distorted image by reducing distortion. Its largest version is 40 (177×177 modules), which can store up to 7089 numerals.

Micro QR Code

This is a smaller version of the QR code, which can only store up to 35 numerals. It has only one Position Detection Pattern . Because of which its size is quite small. This is an ideal QR code for applications that are short of space. Such as the components of the Circuit Board .

IQR Code

This is a Matrix Type 2D Barcode that can be printed in both Rectangle and Square shapes. There are many versions of it. Talking about the Square IQR , there are 61 (minimum 9×9 modules) and 15 versions of Rectangle IQR (minimum 19×5 modules) available. That is, it can be easily printed even in the smallest space.

The IQR code is capable of storing maximum data in the least amount of space. It has a maximum storage capacity of 40,000 Numeric Characters (422×422 Modules). Which is many times more than the largest version of Model 2, 40. Also, its Error Correction Rate is also very high (50%). Because of which the code can be scanned even after half the  code is damaged.

Frame QR Code

There is an empty space in the center of this QR code, which is called QR Code Frame . In this frame, mainly texts, images and graphics are arranged. But it is not limited to just text, images and graphics. It can also be used as different types of designs and white spaces.

Secure QR Code (SQRC)

It is a secure QR code, which protects the data inside it by a cryptographic key . And restricts all the devices that try to access the data. For this, there is a private data segment in it, which is decrypted with the help of an encryption key . It helps to keep personal information secure. Especially, it helps to keep the internal data of companies limited to the people of the company.

However SQRC code is not limited to just private data. It is also used for public information. But Encryption is not used for this. Because this is an option, which is for special sensitive information. The SQRC Code was developed by the Forus Foundation for secure transactions.


HCC2D stands for High Capacity Colored 2 Dimensional Code. That is, high-capacity colored 2D code. This is actually a Color Matrix Code developed by researchers. Which is currently in the prototype phase. It uses colors to increase the data density. But due to this, Chromatic Distortion has to be faced during decoding. And to avoid this problem, HCC2D code uses an additional field (Color Palette Pattern).

JAB Code

JAB means Just Another Barcode . This is a colored QR code made up of a combination of colored squares within a rectangular or square grid. It has 4 or 8 colors. Out of which 4 are primary colors (Cyan, Magenta, Yellow and Black) and 4 are secondary colors (Blue, Red, Green and White). Since colors add a third dimension to a two dimensional matrix. That’s why JAB code can store more data than black and white codes.

If seen theoretically, its 4 color code is able to store 2 times and 8 color code is able to store 3 times more data. But this license is not obtained till JAB Code. Although it was submitted for ISO standardization . But till now the process of standardization is in processing. And currently it is published under the LGPL v2.1 License.

QR Code Versions

While talking about the above QR Code Variants , QR Code Versions were repeatedly mentioned. But the question is, what are these QR code versions? And what is their use? Also how many versions of QR code are there? And which ones? Come on, let’s know.

First let’s talk about the number of versions. So there are a total of 40 versions of the traditional QR code. And each version has different number of data modules. That is, the higher the version number, the higher the number of Data Modules . And the higher the number of data modules, the higher the storage capacity of the QR code. That is, the bigger the version, the more data it will store.

For example Version 1 (21×21 modules) can store up to 25 alphanumeric characters. Whereas Version 2 (25×25 modules) can store 47 characters and Version 3 (29×29 modules) can store 77 characters. Similarly Version 40 (177×177 modules) can store 4296 alphanumeric characters. That is, as the version number increases, so will the number of data modules and storage capacity .

How to Scan QR Code?

Scanning the QR code is very easy. You just need to have a Smartphone with QR Code Reader or Camera . By the way, most people use smartphones only. Because the smartphone is always with us. And it can be used anywhere.

Well, nowadays, QR Code Scanner comes inbuilt in the camera app of most of the smartphones. That’s why the phone’s camera is enough to scan the QR Code. But if your phone does not have this feature then it does not matter. You can download QR Code Scanner or QR Code Reader App by going to Google Play Store . You will find a lot of QR Code App on Play Store .

Apart from this, there are also many online websites, which allow online QR Code Scanning. Such as qrscanneronline, webqr, 4qrcode etc. On these websites, you can check QR Code by uploading a photo or screenshot . QR Code Scanner online or offline, the data shows only what is present inside the QR code.

Well, to scan QR Code with the help of QR Code Scanner App or Camera, open the app or camera and point on the QR code. The QR Code will be scanned as soon as you point. And you will see all the details on the screen.

QR Code Decoding

The help of QR Code Decoder is taken to decode the information present in the QR code . First of all , the QR code is scanned with the help of a Digital Image Sensor . And with the help of a programmed processor , the data is extracted and analyzed. The processor then detects the remaining three classes with the help of the small square or squares near the bottom right corner. And Normalizes the QR Code Image for Size, Orientation and Viewing Angel.

After that converts the small dots (pixels) present in the image into binary numbers. And validates it with the help of Error Correcting Algorithm . Reed Solomon Error Correction is used for this . When the decoding process is complete! So the data present in the QR code is displayed on the screen. In this way the information present in the QR code is decoded.

If we talk about Error Correction, then QR code uses Reed Solomon Code for this. It is actually a set of error correcting codes , which helps to detect and fix wrong symbols. Basically it is used in data storage, data transmission, space transmission and barcodes.

How to Generate QR Code?

Now the question is how to generate QR code? How to generate a QR Code? So it’s very easy. For this you will find many apps and websites. All you have to do is go to the Play Store and search by typing QR Code Generator App . And download a high rated app.

But right there if you want to generate QR Code online! So go to Google and search by typing Free QR Code Generator or QR Code Generator Free . You will find many websites. such as QR-Code-Generator. Come! Let us generate a QR code with the help of this website .

So first of all go to your browser . And open this website. After that select Data Type . For example, if I want to generate a QR code for the URL of my website, I selected the URL. And then typed the below url. You can also upload files here. Well after entering the data , tap on the button of Generate QR Code .

Edit QR Code

Now you will reach the Customization Page. Here you will find many options to edit QR Code . Such as Frames, Shapes, Colors etc. You can customize the QR code according to your need. And when the code is ready, you can download it by clicking on the Download button. Apart from this, you can also download high-quality vector files.

In this way you can generate free QR code for your website, email, mobile number, contacts, social media handle and other important details. For this you will get a lot of QR Code Editor . And you can edit QR Code online from any website .

use of qr code

By the way, the QR code was made for the Automotive Industry. But today it is used in almost every industry. And it has many uses. These are the main uses of QR codes. That is, Main Usages of QR Code :-

  • Advertising Industry: Big companies and brands use QR codes in their advertisements indiscriminately.
  • Online Payment Services: All online payment services like PhonePe, Google Pay, Paytm and Amazon Pay use QR codes.
  • Government: QR code is also used in documents issued by the government such as Aadhaar Card , Janaadhaar, Voter ID Card, PAN Card, caste certificate, domicile certificate etc.
  • Education: QR code is widely used in the field of education. Even in course books (in every lesson) QR codes are used.
  • Retail Industry : QR code is used to track products in the retail industry.
  • Healthcare: From tracking patients to tracking medicines, QR codes are used for everything in hospitals.
  • Information and Technology: QR code is the most used in the field of information and technology.
  • Automobiles: QR codes are used in the automobile industry to track and identify vehicles.
  • Personal use: QR codes are also extensively used for personal use. Such as for VCard , mobile number, email, website, social media links etc.

Apart from this, QR codes have many uses. Such as Contactless Applications , Digital Money, Direct Login etc. As you all know that  QR code is used to login to the desktop version of WhatsApp .

History of QR Codes

QR code was invented in 1994 by a Japanese company called Denso Wave . And originally it was made to track vehicles But gradually its popularity increased so much that it became the most used 2D code. Although initially it was made only for the Automotive Industry. But due to Fast Scanning and Quick Response, it became increasingly popular. and adopted by various industries.

By the way, Smartphone has a big hand in the success of QR code. Before the advent of the smartphone, it was limited to industrial areas only. But after the advent of Smartphone, it reached door to door. And COVID-19 has just put wings on its feet. The number of people scanning QR codes has increased incredibly during the Corona pandemic.

Inventor of QR Code

Now the question is, who invented the QR code? Who invented the QR Code? So the credit goes to Masahiro Hara . That is, the QR code was invented by Masahiro Hara. He was an engineer at Denso Wave Company and worked on Barcode Scanners. But barcodes could not store much data.

That’s why he thought of working on a code which is faster than the barcode. Be able to store more data. Thinking this, he started work on a 2 Dimensional Barcode in 1992. And after two years of tireless effort, QR Code was invented in 1994. It was an advanced 2D barcode, which was not only fast in scanning. Rather, it was also quite fast in terms of response. And was able to store many times more data than barcodes.

How secure is the QR code?

Although QR code is quite secure but not completely secure. Through this, malicious code can be inserted into the user’s phone or computer. And with the help of Attagging the user can be tracked. If you are a smartphone user. And if you scan any QR code without thinking, then be careful! Your privacy may be at risk.

Because QR Code Reader has a lot of permissions like Camera to Full Internet Access, Network, Contacts, Storage, Read/Write Data, Browsing History, GPS and Global System Change . Through which the user can be spied. Also data can be stolen from the device.

Because when you look from outside, it is not known what is hidden inside which QR code? Anything can happen inside it. There may even be some malicious code. Can be any script. Or it can be a URL, which can host any JavaScript code . and exploit system vulnerabilities. That’s why never scan any QR code without thinking.

QR Code : FAQs

Question 1. What is QR Code?

Answer: A QR code is a machine readable 2D barcode that stores information within a square grid. And uses Squares and Dots for this.

Question 2. What is the full form of QR Code?

Answer: The full form of QR Code is Quick Response Code .

Question 3. Who invented QR code?

Answer: The QR code was invented by Masahiro Hara .

Question-4. How many types of QR codes are there?

Answer: There are basically 2 types of QR codes. One, Static QR Code and the other Dynamic QR Code (Dynamic QR Code)

Question-5. How many versions of QR codes are there?

Answer: There are 40 versions of the traditional QR code.

Question-6. How to make your own QR Code?

Answer: Creating a QR Code is very easy. There are many QR Code Generator Websites available for this. You can go to any website and enter your details. And can generate Free QR Code. As mentioned in the “How to generate a QR Code” section above.

Question-7. How to scan QR code from phone?

Answer: Very easy. First of all open the Camera app. And point it on the QR code. Doing so will automatically detect the QR code. And the information contained in it will be shown on the screen. If your phone does not have this feature then you can download QR Code Reader App or QR Code Scanner App from Google Play Store .

Question-8. What is the Reed Solomon Code?

Answer: Reed Solomon codes are actually a set of error correction codes . Which helps in detecting and fixing errors.