QR codes: how they work and where they are used
Design of QR codes, error correction standards, application in business. How to create QR for Wi-Fi, business cards, menus and links.
How does a QR code work?
QR (Quick Response) is a two-dimensional barcode invented in Japan in 1994. Can contain up to 4296 ASCII characters or 7089 digits.
What it consists of:
- Search patterns - three squares in the corners for orientation
- Alignment patterns - for bending correction
- Timing patterns - grid for cell size
- Data blocks - actual information with error correction
Error correction levels
| Level | Recovery | Application |
|---|---|---|
| --- | --- | --- |
| L (Low) | 7% | Data storage |
| M (Medium) | 15% | General Use |
| Q (Quartile) | 25% | Industry |
| H (High) | 30% | Branded QR with logo |
A high level of correction allows you to add logo on top of the QR code - up to 30% of the area can be covered.
Application in business
Wi-Fi connection → WIFI:S:'<'SSID'>';T:WPA;P:'<'password'>';;
Link → https://example.com
Email → mailto:hello@example.com
Phone → tel:+79001234567
Business card (vCard) → BEGIN:VCARD...END:VCARD
Geolocation → geo:55.7558,37.6176 Wi-Fi QR code for cafes
Let guests connect to Wi-Fi with one scan—no password required. Print it out and place it on your desk.
Create a QR code for Wi-Fi in 30 seconds - free, with choice of protection and configuration.