How QR Codes Work Under the Hood
A QR code (Quick Response code) encodes data as a matrix of black and white modules arranged in a square grid. Unlike linear barcodes that store data in one dimension, QR codes store information in two dimensions — both horizontally and vertically — allowing them to hold up to 4,296 alphanumeric characters or 7,089 numeric digits in a single code.
The code includes three finder patterns (large squares in corners) for orientation detection, alignment patterns for perspective correction, timing patterns for module-grid calibration, and a format information area that specifies the error correction level and mask pattern. This redundant design is what makes QR codes scannable from any angle, even when partially damaged.
Error Correction Levels Explained
| Level | Recovery Capacity | Code Size | Recommended For |
|---|---|---|---|
| L (Low) | ~7% of data | Smallest | Digital screens, clean environments |
| M (Medium) | ~15% of data | Standard | General purpose — best default choice |
| Q (Quartile) | ~25% of data | Larger | Printed materials, packaging |
| H (High) | ~30% of data | Largest | Logo overlays, outdoor signage, harsh conditions |
PNG vs SVG: Choosing the Right Export Format
PNG (Raster)
- Fixed resolution — perfect at its generated size
- Best for websites, social media, email signatures
- Universally supported in all browsers and apps
SVG (Vector)
- Infinite scalability — crisp at any size from thumbnail to billboard
- Best for print: business cards, posters, merchandise
- Smaller file size, editable in Illustrator and Figma
Popular QR Code Use Cases
Restaurant Menus & Ordering
Replace physical menus with a QR code linking to a digital menu. Customers scan from their table to browse, order, and pay — reducing wait times and printing costs.
Wi-Fi Network Sharing
Encode your network name, password, and security type into a QR code. Guests scan to connect instantly — no typing long passwords or asking for credentials.
Business Cards & Networking
Add a QR code to your business card linking to your LinkedIn, portfolio, or vCard. Recipients scan instead of manually typing your contact details into their phone.
Event Tickets & Check-In
Generate unique QR codes per attendee for paperless event entry. Scanning validates the ticket instantly, prevents duplication, and speeds up check-in lines.
Want to go deeper?
Read our complete guide on how QR codes work, customization options, and best practices for print & digital — with real-world use cases for marketing, Wi-Fi, and payments.