How a QR Code Works and How to Create Yours Safely and Efficiently
The QR Code, short for Quick Response Code, is one of the most popular two-dimensional barcode formats in the world. Created in Japan in 1994 by Denso Wave, it was initially developed to track automotive parts during manufacturing processes. Over time, its use expanded to almost every industry: marketing, payments, logistics, events, education, and even personal applications.
Today, it serves as a direct bridge between the physical and digital worlds. By simply pointing your smartphone camera at a QR Code, you can open a link, make a payment, access a file, or even verify your identity. But how does this technology actually work? And how can you create a QR Code that is both safe and efficient? Let’s explore that in detail.
What is a QR Code
A QR Code is a two-dimensional barcode that stores information in a pattern of black and white squares arranged within a square grid. Unlike traditional barcodes that store data only horizontally, QR Codes store data both horizontally and vertically. This allows them to contain much more information in a smaller space.
QR Codes are designed for quick reading, even when partially damaged or printed in small sizes, thanks to built-in error correction features.
QR Code Components
- Position Markers – Three large squares in the top-left, top-right, and bottom-left corners that allow the reader to identify the code’s orientation.
- Quiet Zone – A blank margin around the code, essential for avoiding reading interference.
- Alignment Pattern – Alternating lines of black and white pixels that help the scanner determine the code’s size and proportions.
- Data Area – Where the actual information (URL, text, number, etc.) is stored.
- Error Correction Block – Stores redundant data to allow reading even if part of the code is damaged.
How QR Code Reading Works
- Image Capture – The reader detects the QR Code image.
- Position and Orientation Identification – Position markers allow the system to understand the code’s orientation.
- Decoding – The pixel pattern is converted into binary data.
- Interpretation – The binary is translated into its original format (URL, text, vCard, etc.).
- Automatic Action – The device automatically executes the associated action.
Storage Capacity
- Numeric – up to 7,089 characters.
- Alphanumeric – up to 4,296 characters.
- Binary – up to 2,953 bytes.
- Kanji/Kana – up to 1,817 characters.
Types of QR Codes
Static QR Code
Stores fixed data that cannot be changed after generation. Ideal for permanent information.
Dynamic QR Code
Allows changing the target even after printing. Commonly used in campaigns, promotions, and tracking.
Best Practices for Creating a Safe QR Code
- Use trusted URLs.
- Test before distributing.
- Avoid excessive customization that could hinder readability.
- Maintain high contrast between code and background.
- Prefer HTTPS links.
Practical Applications
QR Codes are used in marketing, payments, access control, education, and logistics. They connect users quickly and efficiently to digital content and services.
Security and Fraud Risks
Risks include malicious QR Codes and physical tampering. Always check the URL before clicking and use trusted scanning apps.
How to Create Your QR Code
- Choose the type (static or dynamic).
- Enter the content.
- Customize if desired.
- Generate and test.
- Download and use.
QR Codes in Brazil and Worldwide
In Brazil, QR Codes became popular with the PIX payment system. Worldwide, Japan and China lead in usage, especially for payments.
FAQ
Do QR Codes expire? Static codes do not expire; dynamic codes may expire depending on the service.
Can I track QR Code scans? Yes, with dynamic QR Codes.
Do they work offline? Yes, if the content does not require internet access.
Conclusion
QR Codes are simple yet powerful. By understanding how they work and creating them securely, you can ensure efficiency and convenience, connecting people and businesses directly.