QR codes turn any URL into a scannable image. They are the fastest way to share links in the physical world — on business cards, flyers, menus, and product packaging.
What Can a QR Code Contain?
- URLs — Any website link
- WiFi credentials — SSID, password and security type for instant guest network access
- Contact details — vCard format with name, phone, email
- Text — Any plain text up to approximately 3KB
- Email and SMS — Pre-addressed emails or messages
How to Generate a QR Code
Use Anonymiz QR Code Generator — it supports URLs, WiFi, vCard, text and email formats. Generated QR codes download as PNG or SVG. No account needed, completely free, no watermarks.
How QR Codes Actually Store Data
A QR code encodes data using a grid of black and white squares governed by the Reed-Solomon error correction algorithm — the same math used in CDs and satellite communications to recover data from damage or noise. This is why a QR code can still scan correctly even with a logo overlaid on part of it or a corner slightly torn: the error correction level (L, M, Q, or H) determines what percentage of the code can be obscured or damaged while still decoding correctly, with Level H tolerating up to 30% data loss.
A Common Design Mistake
Inverting colors — a light code on a dark background, done for aesthetic reasons — breaks scanning on many older or budget scanner apps, which specifically expect dark modules on a light background and misread the inverted pattern as noise. Similarly, adding decorative gradients or low-contrast color schemes can reduce the effective contrast below what scanners need, even when a human eye can read it fine. Testing on several different phones and scanner apps before finalizing a design catches both issues before printing.
QR Code Best Practices
- Test before printing — Always scan your QR code with multiple devices before mass printing.
- Add error correction — Use Level H (30% error correction) for physical materials that may get worn.
- Use high contrast — Dark code on light background for reliable scanning.
- Minimum size — At least 2cm x 2cm. Larger for materials viewed from distance.
QR Codes for WiFi
Create a QR code for your guest WiFi so visitors can connect without typing a password. Pair with Anonymiz WiFi Password Generator to create a secure password and then generate its QR code instantly.
