Payload Configuration
Supports HTTP, HTTPS, deep app links (e.g. spotify:, tel:, intent:).
Visual Customization & Styling
Live Preview
Ready to scanHow QR Codes Work: Matrix Anatomy & Encoding
Invented in 1994 by Masahiro Hara at Denso Wave, the Quick Response (QR) code is a two-dimensional matrix barcode capable of encoding numeric, alphanumeric, byte, and Kanji characters. A modern QR code contains several distinct functional zones that allow smartphones and high-speed industrial optical scanners to detect, orient, and decode data within milliseconds:
Position Finder Patterns
Three large nested squares situated in the top-left, top-right, and bottom-left corners. They allow the scanner to identify the code's physical orientation from any 360-degree angle.
Timing & Alignment Tracks
Alternating dark and light module lines connecting the finders. They calibrate grid coordinate intervals, while smaller alignment patterns correct for physical surface curvature and camera perspective tilt.
Quiet Zone (Margin)
A minimum 4-module blank border surrounding all four sides of the QR matrix. This empty border prevents surrounding graphics, text, or packaging borders from interfering with edge detection.
Reed-Solomon Error Correction Levels (ECC)
QR codes embed mathematical polynomial redundancy using Reed-Solomon error correction codes. Higher error correction levels permit the code to be reliably scanned even if dirt, scratches, tears, or center logos cover a portion of the modules.
| Level | Recovery Capacity | Matrix Density | Recommended Use Case |
|---|---|---|---|
| Level L | ~7% restoration | Lowest (Largest modules) | Clean screen displays, thermal receipt printing with dense text payloads. |
| Level M (Default) | ~15% restoration | Standard | Standard marketing materials, brochures, restaurant table menus, packaging. |
| Level Q | ~25% restoration | High | Subtle branding, small center icons, outdoor banners exposed to light weather. |
| Level H | ~30% restoration | Highest (Compact modules) | Prominent center logos/emojis, industrial factory tags, harsh weather usage. |
Wi-Fi & vCard Standards
Specialized mobile actions rely on standardized text schemes. When a mobile operating system parses these prefixes, it launches the appropriate native handler:
- Wi-Fi: WIFI:T:WPA;S:NetworkName;P:Password;H:false;;
- vCard 3.0: BEGIN:VCARD\nVERSION:3.0\nN:Doe;John\nTEL:+1...\nEND:VCARD
- Email: mailto:user@domain.com?subject=Hello&body=Hi
Print & Scannability Rules
- Maintain High Contrast: Ensure at least 4.5:1 contrast between foreground modules and the background. Dark foreground on light background is always most reliable.
- Preserve the Quiet Zone: Never crop the white margin around the QR code. Keep at least 4 modules of clear buffer space away from graphics or text.
- Use Vector SVG for Large Formats: When designing billboards, banners, or high-DPI print collateral, export in SVG or PDF format to prevent raster pixelation.
Frequently Asked Questions
What are the four QR code error correction levels (L, M, Q, H)?
QR codes use Reed-Solomon error correction algorithms to reconstruct obscured or damaged data. Level L restores up to 7% of missing data, Level M (standard default) restores up to 15%, Level Q restores up to 25%, and Level H restores up to 30%. If you overlay a center logo or icon over your QR code, we strongly recommend using Level Q or Level H to guarantee high scannability.
How does the Wi-Fi QR code connection protocol work?
Wi-Fi QR codes encode credentials using the standard MECARD format: WIFI:T:WPA;S:MySSID;P:MyPassword;H:false;;. When scanned by iOS (Camera app) or Android (Google Lens / Camera), the operating system automatically detects the network payload and prompts the user to connect with a single tap without manually typing passwords.
What is the recommended minimum print size for a QR code?
For reliable scanning at standard reading distances (10–12 inches or 25–30 cm), a printed QR code should measure at least 2 × 2 cm (0.8 × 0.8 inches). A practical rule of thumb is a 10:1 distance-to-size ratio: if the scanner will be 1 meter away, the QR code width should be at least 10 cm.
Are generated QR codes permanent, and do they ever expire?
Yes, all QR codes generated with this tool are 100% static. The encoded data is directly baked into the 2D matrix itself. Because there is no intermediate redirect server or tracking URL, your QR codes will work indefinitely without subscription fees, expiration dates, or scan limits.
Is my encoded information stored or tracked on your servers?
No. All QR code matrix calculations, canvas rendering, gradient compositing, and vector exports happen entirely inside your web browser via client-side JavaScript. Your text, passwords, contact details, and cryptocurrency addresses are never transmitted to or stored on any remote server.
Related Developer & Converter Tools
Color Code Converter
Convert color formats between HEX, RGB, HSL, and CMYK with color previews.
CSS Pattern Generator
Generate geometric CSS background patterns with live preview and code export.
CSS Layout Generator
Design responsive CSS Grid and Flexbox layouts visually with device sandboxes.
Unicode Punycode Converter
Encode internationalized domain names (IDN) to Punycode ASCII and vice-versa.