QR codes from A to Z: the complete guide
QR code is a two-dimensional barcode consisting of black and white dots that can encode up to several hundred characters. Nowadays, smartphones and tablets c…
What is QR code?
QR code is a two-dimensional barcode consisting of black and white dots that can encode up to several hundred characters. Nowadays, smartphones and tablets can recognize and decode them very quickly - QR stands for Quick Response.
How is QR code used?
Due to the increasing use of smartphones, QR codes are also being used for broader marketing purposes. Advertisers benefit from QR codes by adding digital content such as websites, videos, PDFs, images, or contact details to flyers, posters, product catalogs, and business cards.
How to create a QR code?
With Qrcode-gen, QR codes can be generated in just a few seconds with 3 simple steps: First: Choose the function for your code (website link, name card, Facebook, Wi-Fi, etc.) Second: Enter the content you want to provide to your customers, customize it with colors, add icons, or use the default QR code style. Third: Click the "Generate QR Code" button. Your QR code is ready to be downloaded and printed.
Can QR codes be customized?
Yes. Due to its high error correction capacity, QR codes can be modified to a certain extent without affecting readability. For example, you can choose new colors and backgrounds, place your company logo in the center of the code, and change the design of the three special points. Remember to ensure that your QR code works by testing it with smartphones and QR code readers.
What are static and dynamic QR codes?
Dynamic QR codes: With this type of code, we can modify the functions and target addresses, even after they have been printed. They also allow us to collect statistical data related to the number of code scans, locations, as well as the exact date and time of access. Dynamic codes use a shortened URL to redirect users to the desired target address. Static codes do not provide these features but directly link to your content without the need for any URL (no internet connection required).
How can we measure the number of QR code scans?
It is possible to measure or track the number of scans for dynamic QR codes. A forwarding URL is connected to the corresponding provider's server to collect relevant data. All information during this period will be directly available in your account.
What should I consider before printing?
We recommend using high-resolution file formats for printing. In addition to JPG and PNG files, vector formats like EPS and SVG are also suitable. These two formats are particularly useful for larger print sizes as they can be scaled without affecting the quality. To ensure safety, it is advisable to perform a physical test before the final output.
Other important aspects related to QR code printing
In addition to file formats, other relevant aspects need to be considered. In general, determine the print size based on the number of characters encoded. If the content is heavily encoded, a larger size is required. A size of approximately 2x2 cm is usually sufficient for most cases. It is also better to avoid uneven surfaces as wrinkles on paper can negatively affect code readability.
How can QR codes be scanned?
Simply using a mobile phone or tablet with a QR code reader app allows you to scan QR codes. These code reader apps are available and free to download from app stores. Cameras on iOS 11 devices automatically recognize QR codes. To scan a code, launch the app and wait for the camera to detect it automatically. Within a few seconds, the encoded content will be displayed on the screen.
How can QR codes be used successfully?
Put yourself in the position of the target user and ask yourself if you would scan the code you see. What value or useful information does the code offer? Do you expect something valuable or helpful from it? Users interact with your advertising and also hope to receive something in return. Present your content using a mobile-optimized web page with an appropriately adjusted display size to make users feel comfortable. Provide valuable content and make your code attractive to people by using various customization options. A simple call to action like "Scan this code to learn more" has been proven successful and will certainly encourage more viewers.
The history of QR codes
The QR code system was invented by Denso Wave in 1994. Its primary purpose was to track vehicles during the manufacturing process, designed to allow high-speed scanning of parts. Although the initial applications were only for tracking vehicle parts, QR codes are now used in various contexts, including commercial tracking applications and applications aimed at convenience for mobile phone users. QR codes can be used to display text for users, add a vCard business card to a user's device, open a website link, or compose an email or message. Users can create and print their own QR codes for others to scan and use to access paid and free content through QR codes. It has become one of the most widely used types of two-dimensional barcodes.
Applications of QR codes
The applications can be almost limitless, especially when encoding URLs with various content. They include homepages, product websites, videos, image slideshow pages, discount coupons, contests, contact forms, or any other form of online content, social media profiles, and more. Many other types of content don't even require an internet connection, such as calendar events, WiFi connections, or vCards containing personal contact information that can easily be added to an address book. QR codes can be placed on websites, printed advertisements, products, or any other flat surface.
Benefits of QR codes for businesses
QR codes offer practical benefits for businesses connecting customers to digital content. First, QR codes shorten the user journey. Instead of typing a long URL, customers can scan and access content instantly—often improving conversion rates. They can also reduce marketing costs because codes can be printed on packaging, flyers, and signage without reprinting every time you update content (especially with dynamic QR codes). Another major benefit is measurement: businesses can track scan counts, timing, and locations to optimize campaigns.
Types of data you can encode in a QR code
QR codes are not only for websites—they can hold many kinds of data. For example, you can encode URLs, plain text, phone numbers, email addresses, or WiFi details. QR codes also support contact cards (vCard), calendar events, and even map locations. Because of this flexibility, QR codes are used in many scenarios from personal use to enterprise workflows.
How do QR codes work?
A QR code encodes data as a grid of black and white modules following a defined structure. When someone scans the code, the camera detects the finder patterns and decodes the payload. The device then turns that data into an action—such as opening a website or showing content. This design enables fast, reliable reads even when the code is tilted or partially damaged.
QR code error correction levels
One strength of QR codes is error correction (damage tolerance). There are four levels: • Low (L): recovers about 7% of codewords • Medium (M): about 15% • Quartile (Q): about 25% • High (H): about 30% That means a QR code can still scan even if it is scratched or partially covered.
What QR code size is appropriate?
QR size should match the expected scanning distance. A common rule of thumb is that scan distance is roughly 10× the printed module size (or the overall code width). For example, a ~2 cm wide code is often comfortable to scan from about 20 cm away. For large out-of-home ads, use a larger QR code so it remains easy to scan from farther away.
Common mistakes when using QR codes
Poor placement or design can reduce effectiveness. Typical issues include codes that are too small, placed too high, poorly lit, or using low contrast colors—making them hard to scan. Another mistake is linking to pages that are not mobile-friendly, which hurts the post-scan experience.
Security considerations for QR codes
QR codes are convenient, but they can also be abused. Users may be redirected to malicious sites if they scan untrusted codes—so it is best to scan codes from reputable sources. For businesses, use HTTPS destinations and keep destination content under control to protect end users.
QR codes vs traditional barcodes
Both store data, but they differ in capability. Traditional 1D barcodes hold limited information and usually require a specific scan orientation. QR codes can store more data and can be scanned from multiple angles. QR codes also support stronger error correction, which helps reliability in real-world conditions.
Future trends for QR codes
QR usage continues to grow alongside mobile adoption. In the future, QR codes are likely to be embedded deeper into payments, identity verification, personalized marketing, and IoT workflows. Combining QR interactions with technologies like AI and analytics can also help businesses understand user behavior more clearly.
When should you use a QR code?
QR codes are a strong fit when you want to move people from offline to online quickly. They work well for sharing information, payments, promotions, and digital content delivery. However, use a QR code only when it adds value—if users can reach the content easily without scanning, a QR code may not be necessary.