QR Codes: How They Work and How to Make Your Own
QR codes are everywhere but how do they actually work? Here's a plain-English breakdown plus a free tool to generate them.
QR codes (Quick Response codes) are everywhere — restaurant menus, business cards, event tickets, and product packaging. But how much do you really know about them?
What is a QR Code?
A QR code is a 2D barcode that can store:
- URLs — link to websites
- Text — any plain text information
- WiFi credentials — network name and password
- Contact info — vCard format for business cards
- Email addresses — pre-fill recipient and subject
How to Create a QR Code
Creating a QR code is simple with our free QR code generator:
- Choose a type — URL, text, WiFi, email, or phone
- Enter your data — paste the URL or type your content
- Customize — adjust size and error correction level
- Download — get your QR code as PNG or SVG
QR Code Best Practices
- Test before printing — scan the QR code to verify it works
- Use high contrast — black on white works best
- Add quiet zone — leave white space around the QR code
- Consider error correction — Level H (30%) for printed codes
- Keep it simple — shorter URLs = smaller, faster-scanning codes
Creative Uses for QR Codes
- Business cards — link to your portfolio or LinkedIn
- WiFi sharing — let guests connect without typing passwords
- Event tickets — scan for check-in
- Restaurant menus — link to digital menu
- Product packaging — link to user manuals or tutorials
Try our QR code generator to create your first code — it's free and takes seconds.
## QR Code Use Cases Beyond Menus
QR codes have expanded far beyond restaurant menus and event check-ins. Here are practical applications:
- WiFi sharing: Encode SSID and password so guests can connect without typing
- Contact sharing (vCard): Put a QR code on a business card so people can save your contact info by scanning
- Payment links: Stripe, PayPal, and other payment processors generate QR codes for checkout
- Product authentication: Luxury brands embed QR codes to verify authenticity
- Inventory tracking: Warehouses use QR codes for fast, accurate stock counts
- Event tickets: Concerts and conferences use rotating QR codes to prevent screenshot fraud
- Educational content: Teachers link worksheets to video tutorials via QR codes
QR Code Error Correction Levels
QR codes use Reed-Solomon error correction, which means they still work even when partially damaged or obscured. There are four levels:
| Level | Recovery | Use Case |
|---|---|---|
| L (Low) | 7% | Maximum data capacity, clean environments |
| M (Medium) | 15% | Default, general purpose |
| Q (Quartile) | 25% | Industrial, some dirt expected |
| H (High) | 30% | Outdoor, harsh environments |
Higher error correction means the QR code can tolerate more damage but holds less data. For most web use, level M is fine. For printed materials that might get wet or dirty, use level H.
Designing Custom QR Codes
Modern QR codes do not have to be black squares on white backgrounds. You can:
- Change colors: Use any dark color on any light color, as long as there is sufficient contrast
- Add a logo: Place a small logo in the center (keep it under 30% of the QR code area)
- Round the modules: Replace square dots with circles or rounded squares
- Add gradients: Some scanners handle gradient fills, though this reduces scan reliability
Always test custom QR codes with multiple devices and scanning apps before publishing. What looks good on screen may not scan reliably in real-world conditions.