How Do QR Codes Work? – Revealing The Magic of QR Codes

how does a qr code work

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QR codes, short for Quick Response codes, are a modern marvel in the way of technology and accessibility. They have become a popular way for businesses to communicate with customers in our current touchless society.

QR codes have been around for decades but have seen a tremendous increase in usage since the SARS-COVID-19 pandemic. According to Statista, in the United States alone, 11 million households scanned a QR code in 2020, a significant increase from 9.76 million scans in 2018.

But have you ever wondered how these small, square-shaped barcodes with some kind of strange matrix pattern work? Well, let’s find out!

Before we jump into the secret behind QR codes, we must first learn the basic concept of what a QR code is, its anatomy and its various types. So, without further ado, let’s dive right into it.

What Are QR Codes?

A QR code is a two-dimensional barcode (also called a matrix barcode) made up of square and rectangular modules arranged in a grid-like pattern. It was invented in 1994 by Denso Wave Inc., a Toyota Motors subsidiary that produced automatic identification products, industrial robots, and programmable logic controllers.

QR codes became increasingly popular due to their versatility and ability to store large amounts of data in a small space. In traditional barcodes, the data is encoded in the form of vertical lines or bars with varying widths. On the other hand, in a QR code, data is arranged in both vertical and horizontal directions in the form of squares and rectangle modules.

A QR code can hold numerical digits, alphabets, Kanji characters, and byte/binary data. It can encode a *maximum of 7089 numeric characters, 4296 alphanumeric characters, 1817 Kanji characters (character set according to JIS X 0208) or 2953 bytes of data in a single QR code.

*Please note that the capacity mentioned above is for a version 40 QR code with L ECC (Error Correction Capability) level. QR version 40 has 177 x 177 modules and is currently the largest QR code version.

Anatomy of a QR Code

A typical QR code consists of the following seven distinct parts.

  • Position markers (also called finder patterns, position detection markers and position patterns)
  • Alignment markers
  • Timing pattern   
  • Version information
  • Format patterns
  • Data area
  • Quiet Zone

Position Markers

Position markers are the three identical square structures located at the top right, top left, and bottom left corners of the QR codes.

Position markers help mobile devices and QR code scanners to accurately detect the presence, orientation and size of a QR code in an image.

Position markers of a QR code
Anatomy of Alignment Markers of a QR Code

Alignment Markers

Alignment markers are a square with a black dot in the centre. The position of alignment markers will vary depending on the amount of information the QR code contains. Alignment markers are smaller in size than the position markings.

An alignment marker fine-tunes the alignment of a QR code for accurate scanning. It makes the QR code scannable from all angles and directions. The larger the QR code is, the more alignment markers it will contain.

Timing Pattern

The timing pattern is a series of alternating light and dark modules arranged vertically and horizontally between two position markers.

The timing pattern aids in the configuration of the data grid by determining the central coordinate of each cell in the QR Code. They also help a QR code scanner to determine the size of the modules in QR codes.

What is the Timing Pattern of QR code and its use
Anatomy of a QR Code on Version Information

Version Information

Version information is a pattern surrounding the top right and bottom left position markers and is used to specify the version of the QR code.

A QR code version represents the size (number of modules) of a QR code. It ranges from version 1 to version 40, with version 1 being the smallest with 21 × 21 modules and version 40 being the largest with 177 x 177 modules.

Format Patterns

Format patterns are present around all three position markers and contain information regarding the error tolerance level and data mask pattern details. They help to make QR codes easier to read and scan.

Position and use of format Patterns of QR code
Anatomy of a QR Code about Data Area

Data Area

The data area is the core component of a QR code. It holds the data modules containing the actual encoded information and Reed-Solomon codes for error correction functionalities.

The size of the data area depends on the following three factors.

  • Type and amount of information encoded
  • Chosen error correction level (ECL)
  • Level of custom designing done

Quiet Zone

The quiet zone is the empty margin or space surrounding all four sides of the QR code that separates the barcode from other elements in the image.

A quiet zone helps the QR reader accurately detect the QR code’s presence. It also helps determine from where the QR code begins and ends.

To achieve maximum scannability success, ensure that the QR code is surrounded by a “quiet zone” of approximately 15% of the entire QR code dimension. Follow our QR code best practice guide for more tips and tricks on creating QR codes that engage and convert your customers.

Quite Zone of a QR code

Types of QR Codes

Types of QR Codes

There are two types of QR codes – Static QR Code and Dynamic QR Code.

Static QR codes are the traditional form of QR barcode that cannot be modified without re-creating, re-printing and re-deploying the entire QR code. These codes contain the actual information instead of a link to the information.

On the other hand, Dynamic QR codes are more advanced versions of QR barcodes. These codes are much more flexible as they can be edited and updated at any time without replacing the entire code.

Dynamic QR codes contain a URL that redirects the users to an online resource or webpage with relevant information. They also enable users to track the performance of their QR codes by gathering different metrics such as scanning frequency, locations, device types and more.

Please refer to our dynamic vs static QR code comparison guide for a thorough understanding of the differences between these two types of QR codes.

How Do QR Codes Work Technically

How does a QR Code work technically

QR codes, like any other barcode, reflect a beam of light in a pattern that is caught by an optical sensor in the scanner and converted into electronic signals. These electronic signals are passed to a processor, which decodes them and delivers the stored information to the user.

Let’s now take a deep dive into the technical aspects of how QR codes work.

Here’s a basic five-step explanation of how the QR code scanning process works once you scan QR codes via the device’s camera or barcode scanner.

  1. The scanner starts by recognizing the QR code. To identify a QR code, the scanner first recognizes the three position markers and then the quiet zone to identify the edges of the QR code.
  2. Once the QR is successfully identified, the scanner begins at the bottom right, where it finds the mode indicator. Mode indicator has 4 data modules that indicate the data type (numeric, alphanumeric, byte, or kanji) encoded in the entire QR code.
  3. Next, the scanner moves up from the mode indicator, where it encounters the character count indicator. The character count indicator has 8 data modules that represent the total number of characters in the encoded data.
  4. After knowing the data types and character length, the scanner proceeds along the data modules in a zig-zag pattern until it retrieves all of the encoded information and reaches the stop indicator.
  5. After reading all the data and reaching the stop indicator, the scanner continues its path to the error correction data modules. Error correction data modules have backup data stored in them which helps retrieve stored data even if a few modules of the QR code are damaged.

Are QR Codes Dangerous?

QR codes are not dangerous; they are a simple and convenient way to store and share information.

However, just like clicking and visiting random links or websites is risky, scanning random QR codes is also dangerous.

Malicious actors exploit the convenience of QR codes for their own nefarious purposes by embedding links to phishing sites, malicious websites, virus-infected apps and other malicious content.

With that in mind, it is important to ensure that the QR codes you scan are from reliable and trusted sources. Never download strange third-party applications or a file after scanning QR codes.

How Do I Generate QR Codes?

QR codes are a public domain technology, which means they are not owned by a single person or company, and there are no license restrictions or costs associated with their use. As a result, there are numerous free online QR code generators on the Internet.

However, a free QR code generator does not offer the same level of customization, security, or support as paid QR code generators. Therefore, we recommend utilizing paid tools and software to create and manage QR codes.

One software that we highly recommend to our customers is Seagull Scientific’s BarTender Software.

The BarTender is one of the most popular label designing and printing software. This tool helps you to create labels with images, texts, bar codes, and RFID tags, as well as automate and manage the entire labelling operations.

BarTender software helps you in designing and customizing different types of QR codes, such as.

  • GS1 QR code
  • iQR code
  • Micro QR codes
  • QR code
  • GS1 digital link QR code (01)(90)
  • GS1 QR code (01)(8200)

As an official reseller of Seagull Scientific BarTender Software, Triton is proud to provide customers with a comprehensive selection of all four BarTender editions. We offer Starter Edition, Professional Edition, Automation Edition and Enterprise Edition, all at highly competitive prices. Give BarTender a chance and see how it can streamline your processes and help make barcode labelling tasks more efficient.

Contact us today via the live chat widget below to learn more about BarTender software. Our friendly customer service team will be happy to answer any of your questions.

Frequently Asked Questions

How Far Away Do QR Codes Work?

The distance from which a QR code can be scanned depends on the size of the QR code. According to the standard rule, the ideal ratio of scanning distance to QR code size is 10:1.

Follow our QR code size guide to learn and understand more about the basics of QR code sizing.

How Long Do QR Codes Work / Do QR Codes Expire?

QR codes do not expire, and information stored in QR codes can be accessed as long as they are readable. However, the accuracy of a QR code scan may deteriorate over time due to dirt, scratches or damage caused by other factors.

Please note that if you are using dynamic QR codes, where the information is stored in an online database and linked to the QR code, the data will only be readable if the URL associated with it remains active. Additionally, if you have created a dynamic QR code using software that requires renewal fees and failed to renew the code in time, then the QR code will stop working.

What is One Advantage of a QR Code Over a Bar Code?

The main advantage of QR codes over barcodes is that QR codes can store much more information than barcodes. QR codes also support various data types, giving users the freedom to use them for a range of applications.

Refer to our QR code vs barcode comparison guide to learn more.

Do Screenshots of QR Codes Work?

Yes, screenshots of QR codes will work as long as the screenshot is clear and not blurred.

Wrapping Up

QR codes have become increasingly popular over the past few years as more businesses embrace digital marketing strategies and look for ways to engage customers in new ways. QR codes’ ability to store data and quickly share it makes them an invaluable tool for marketers looking for creative ways to reach their target audiences. 

We hope that this article has been useful in helping you to understand how do QR codes work.

Thanks for reading!

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