What is a QR Code and How Does It Work?
Published: May 2025
QR codes (Quick Response codes) are two-dimensional barcodes that store a large amount of data in a compact format. They can be read quickly by digital devices such as smartphones, tablets, and barcode scanners. Originally developed in Japan by Denso Wave for tracking automotive parts, QR codes are now used globally across various industries.
How Do QR Codes Work?
A QR code consists of black modules (square dots) arranged in a square grid on a white background. These patterns can encode information like URLs, plain text, phone numbers, and more. A scanning device uses an optical sensor to detect the code and decode the data instantly.
Common Uses of QR Codes
- Marketing & Advertising (e.g. posters, flyers, business cards)
- Restaurant menus and contactless ordering
- Mobile payment systems and banking apps
- Product packaging for authentication or information
- Wi-Fi network sharing
Are QR Codes Safe?
While QR codes themselves are safe, the content they lead to might not be. Always verify the source before scanning a QR code, especially if it redirects to a URL. Malicious actors can use QR codes for phishing or malware distribution.
Can QR Codes Expire?
QR codes do not expire on their own, but the destination they link to (such as a website) may become inactive. Dynamic QR codes can be updated or deactivated by the service provider.
How to Scan a QR Code
Most smartphones come with built-in QR scanners in their camera apps. Simply open your camera, point it at the QR code, and tap the notification that appears. Alternatively, you can use a dedicated QR code scanner app.
Create Your Own QR Code
You can easily generate custom QR codes using our QR Code Generator on 72zq.com. It’s free, fast, and requires no signup.
FAQ
Can I use a QR code for a long URL?
Yes, but it may generate a denser code. Consider using a URL shortener first.
Do QR codes need internet to work?
Scanning doesn't require internet, but if the code redirects to a website, you’ll need an internet connection to access it.
Can I customize the design of my QR code?
Yes! You can change colors, add logos, and even embed images with advanced QR generators.