Guide
What is a QR code and how does it work?
Published
A QR code is a square pattern of dark and light modules that stores data such as a web address, text or Wi-Fi details. A phone camera reads the pattern and turns it back into that data. QR stands for quick response.
Where QR codes come from
The QR code was invented in 1994 by Denso Wave to track car parts. It is now used for menus, tickets, payments and links.
How a QR code works
- The three large squares in the corners tell a scanner where the code is and which way it is turned.
- The remaining modules encode the data as a pattern of dark and light squares.
- Built-in error correction lets a code scan even if part of it is dirty or damaged.
What a QR code can store
A link, plain text, Wi-Fi login, phone number, email, WhatsApp chat or contact card. More data means a denser, harder-to-scan code, so shorter content scans better.
Static and dynamic codes
A static code holds the data directly and never changes. A dynamic code holds a short redirect link so the destination can be edited and scans counted, which usually needs a paid service. DailyBox makes static codes.
Scan safely
- Check the address your phone shows before you open it.
- Be careful with codes stuck over other codes or sent by strangers.
- Never enter payment or login details on a page you reached from an unknown code.
Make your own
You can create one in a minute with the QR code generator. For a business setting, read how to create a QR code for your business.
Questions and answers
Do QR codes expire?
Static codes do not. A dynamic code can stop working if the service behind it is cancelled.
Do I need an app to scan one?
Most phone cameras can read QR codes without a separate app.
Can a QR code be dangerous?
The code only holds data, but it can point to a harmful link. Check the address before opening it.