QR codes

What is a QR code?

QR codes store information and make it accessible. QR is the initials of Quick Response and this name does them justice, since a scanner processes data and executes orders at the moment. Any camera, be it a smartphone or tablet , can read these codes with the appropriate application.


  1. How does a QR code work and what is its graphic made of?
  2. What are QR codes used for?
  3. Are QR codes reliable?
  4. Are QR codes safe?
  5. How do you use a QR code?
  6. How to create a QR code?
  7. What are the best QR code apps?
  8. Advantages and disadvantages of QR codes

How does a QR code work and what is its graphic made of?

A QR code contains a pattern in a square graphic in which information in the form of black and white dots and lines that the application reads has been embedded . A QR code can contain up to 177×177 elements and a text of up to half a DIN A4 page. Expressed in figures, a QR code has a capacity of up to 4296 alphanumeric characters or 7089 decimal digits at the lowest level of error correction. The higher the level of error correction, the less capacity the QR code will have.

The two basic elements of the QR code are:

  1. Three squares in the corners of the code, which serve as orientation to the scanner.
  2. The QR code itself, which is inserted as a pattern and contains the information.

What are QR codes used for?

QR codes are used to store information that must be read quickly. They are found on travel tickets, vending machines, stamps, brochures , posters, and many other places. Often times a URL is embedded in it that interested parties can access by scanning it with an application. However, QR codes can also contain coupons or the information needed by the reviewers on a transportation ticket.

The most used functions are:

  • URL : open a web page in a browser.
  • vCard : create a new contact.
  • Geographic location : shows a location on Google Maps.
  • Text : displays a static text.
  • E-mail : send an email with information.
  • SMS : send an SMS with information.
  • WiFi : connects to a WiFi network.
  • Bitcoin – Make a cryptocurrency transfer.
  • Twitter : redirect to a Twitter profile or post a default text.
  • Facebook : redirect to a Facebook page.
  • PDF – Download a file in PDF format.
  • MP3 : plays a file in MP3 format.
  • App Store : Open the App Store to download an application.
  • Image : Displays an image.

QR codes can also be used in combination with other applications, such as augmented reality applications .

Are QR codes reliable?

QR codes are designed to keep information readable, even if they are dark or damaged. This is achieved by compensating for errors , that is, embedding the information several times. With a high level of security, QR codes can be read even if a third of your information is unreadable. This makes QR codes very reliable when it comes to storing information.

Are QR codes safe?

QR codes have also been used for fraudulent purposes. For this reason, it is recommended that you use an application that first displays the code content before executing the function. This will prevent fraud through codes that lead to malicious web pages . It is important to ensure that the web page follows the HTTPS protocol (that is, that it begins with “https: //”). Avoid going to websites that don’t seem trustworthy.

How do you use a QR code?

QR codes can be used with the help of a smartphone or tablet and an application that scans and processes them. After downloading the application, you will only have to follow the following steps:

  1. Point the camera at the QR code.
  2. Scan or photograph the code.
  3. The application processes it.
  4. The application will run the QR code and ask you, for example, if you want to access the URL provided.

How to create a QR code?

QR codes can be created through applications or web pages . To do this, a function must be selected, such as URL link, text or Wi-Fi, and then the information to be shared must be entered. The code that has been created can be saved as an image file in .jpeg format or as a vector file in .svg format . You can then do whatever you want with it, for example print it on t-shirts, share it via instant messaging or embed it on a web page.

When creating a QR code, it must be taken into account whether it is a static or dynamic code . In the case of a static QR code, a change to the destination URL will cause the code to stop working. With a dynamic QR code, you can adapt the destination URL without causing the code to stop working. Creating a dynamic QR code is a paid service at many providers.

What are the best QR code apps?

The best QR code apps are ad-free, include security features, and are easy to use. There is a great variety of them in the Google Play Store or the App Store. Here is a compilation of the most popular for iOS and Android:

The best QR code apps for Android

  • QR Scanner (Kaspersky Lab): Kaspersky is a very popular security software provider. The same quality standard is what distinguishes your QR code application, showing a preview before executing the functions. With this application you can read any QR code quickly, safely and without advertising.
  • Barcord Scanner (ZXing Team): With this application, you will be able to read not only QR codes, but also product barcodes. In addition, you can create your own QR codes. As a scanner, the application works safely, quickly and reliably. It does not contain advertising and shows a preview of the code.

The best QR code apps for iOS

  • Pre-installed Camera App (Apple): Starting with iOS 11, the iPhone and iPad Camera App can read and recognize QR codes. To do this, select the rear camera and photograph the code. Provides preview and does not contain advertising.
  • Scanbot (doo GmbH): in addition to reading QR codes, with this application you can also scan documents. It recognizes codes easily and also offers a preview of them. It does not contain advertising, but offers an enhanced version to its subscribers. QR codes can be scanned with the basic version.

Advantages and disadvantages of QR codes

Like any technological element, QR codes have advantages and disadvantages. It all depends on how they are used and if they are adapted to the user’s needs. It is advisable to know how to take advantage of the strengths of technology and avoid its weaknesses.

Advantages: speed and diversity of uses

QR codes simplify many processes. For example, it is very easy to access a product’s website if you scan its QR code. You can also use these codes to prevent guests from having to enter the Wi-Fi password. Instead they can connect to the network by scanning the code with their phone. If you are interested in taking advantage of these types of advantages, it is worth using QR codes as they are much faster than entering values ​​manually. If they do not provide a clear advantage for the user, you should avoid using QR codes.

These codes are very versatile. With a good concept, a marketing campaign can be presented in an attractive way and provide quick access to digital content. It is important that the benefits of its use are clearly visible to the user. This means offering you exclusive, fast-access content and the opportunity to receive and share it effectively. With imagination, these codes offer endless possibilities.

Disadvantages: Often use and safety risks are unclear

This range of possibilities tempts you to use QR codes even when they are not necessary. In these cases, users may interpret the codes as a strategy and not want to use them.

In addition, a QR code must be placed in a static and quiet place so that the graphic can be read. A moving location, such as a vehicle, renders the code unscannable and unusable.

Additionally, QR codes can also present security risks . In public places they can be manipulated, and anyone who scans them can be directed to a fraudulent URL. At first glance, it is difficult to tell whether a code has been tampered with or not.

Not all QR code applications offered on the market advise users on which websites not to visit. It is important to pay attention to the page where the application wants to direct us before confirming the action. Be careful with short links like “bit.ly”, which can hide the destination URL . Always try to judge for yourself if the code looks safe or not.

Advantages of QR codesDisadvantages of QR codes
Quick access to informationThe advantages of its use are not obvious
Varied possibilities of useUse problems in certain places
 Security risks

QR codes have become essential in some Asian countries. From paying bills to getting marketing gifts, you can do just about anything with these codes. Despite the initial fashion, in Europe they are rarely used. Even so, used correctly, these little squares can dramatically accelerate day-to-day actions such as entering Wi-Fi networks. They can also be very useful in marketing campaigns.

To ensure their safety, the question that the user must ask is: where does this code direct me? Can I trust your supplier? If you are the creator, be sure to provide the full URL and inform in advance what your QR code will be used for. As a user, it is important to use applications that provide preview and do not automatically execute the code.

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